That sucks, I'm sorry. In my experience if communication has died, there is no other path to a successful relationship. If he won't talk about your issues, he already chose to end it.

Be prepared for separation even before trying to find out why.

First off, really sorry that you're going through this. The end of a relationship
is always difficult.
And yes, I said "the end of a relationship".

Based on what you said (and I believe you, I think you're pretty level-headed, and not a drama queen, who makes up shit just to have something going on), he no longer communicates, you've tried talking to him, it's been going on for months,
it's over.
I don't believe in ultimatums. To me, giving someone an ultimatum is equivalent to emotional blackmail, and it hardly ever works. In most cases, even if the other person acquiesces, it's only temporary, and you're right back to where you were in fairly short order.
He's made his position clear. If he were interested in making the relationship work, he wouldn't be behaving as he is.

Make your own plans. Do not include him in those plans. Begin the execution of
your plans as quickly as possible.
If he's in your house, boot his ass out, with no remorse. No discussion, and no possibility of making you change your mind. Have people present for your own protection.
If you're in his house, make arrangements to move you and yours into another domicile as soon as financially feasible.
If you are both on a lease, find out what your legal obligations are. Take the necessary steps to extricate yourself.

Do not tell him your plans. He has no right to know what you're planning.
If you think there is any danger of violence, be prepared to file for a restraining order, and go FASTER.

I know there are some who will think that I am unnecessarily going straight to
Def-con 5, but I've been through this. I've seen this play out in multiple scenarios for myself, and others.
The ONLY thing that matters is protecting yourself, and any children who may be
effected. His feelings are irrelevant now. He has shown you that he no longer cares about the relationship, therefore, he no longer cares about about your feelings. I'm not saying to be ugly, vindictive, or confrontational in any way.
Actually, that is to be avoided as much as possible.

Don't make excuses for him. He's a grown-ass adult. If he doesn't know how to conduct himself within the context of a relationship, it's not your job to hang out and teach him. He may never learn, and you've got more important things to do.
Good luck going forward. I'm here for you if you need moral support.

Sit him down and have one more talk to him. Make it as obvious as what you are saying to us here. If he doesn't respond, you know how long you have to take.

In fact, you already know, or you'd not be asking. My real advice here is to make sure your partner KNOWS before you move forward.

I would be willing to call it quits. I would guess his actions indicate that he has found someone else and not willing to tell you.

That's a tough one. It seems like you'd know each other well enough to have a sense of what is going on. I'd recommend counselling. A neutral ear is a good thing.

We have to be careful here. If my memory serves me well, you're currently pregnant. That changes the dynamic, like it or not. For some in one way, not the same for everyone. On top of that, psychologically woman and men are completely different (Obviously we do NOT know all details), one scenario could be that you are thinking A and he is just thinking B, simple as that. Other possibility is that men are wired differently and they get bored and tired of the other person from a pure physical stand point, in other words, they may not feel any desire at all but that does NOT mean they don't love their partner anymore. It's just another joke of life and the biggest problem is, the man don't even know/understand/accept it as a problem therefore they can discuss or even bring it to the table. The woman keeps pressing the issue and the man keeps getting frustrated out of not knowing how to handle it and they drift apart more and more slowly and stead. You can pull a string only so much. You can be the adult and try an experiment, as much as your logic will tell you "hell, why me??.. screw him !!!"..but if you can overcome those feelings for a couple of day where you give him space and surprise him with nice gestures like "oh you want to watch this TV show then I'll watch it with you" or any little thing you can think of where you can make him feel comfortable. Here is the best part, if he reacts favorably then I would say you both have a big chance to ride the storm if any of you gives the first step towards caving in somehow. If that doesn't help then the problem is something else. I know you will wonder why am I telling you all this like is your job to carry the burden right now and not him...well that's exactly my point, someone is going to have to do this and I guarantee you, we as man are so stubborn with this things that it won't be him taking any step. Once we get in that loop, it takes the other partner's help to get out of there, again if it is a salvageable situation which I think there is a big chance that it is. If you think I am just full of it then I am very much aware I am taking my chances because I have no doubt you will let me know. That would be ok. Anyhow, I understand you are in a tough spot, I hope this helps.

i would address him and say either we sit down and talk now or I will be leaving soon.If he isn't ready to talk the time to leave is now.

I didn't know about the pregnancy, with that information I would change my answer. Don't give up just yet, consider other ways to communicate. Ask him if he would write down what's bothering him if he won't talk about it. Request he attend couple's counseling with you. Maybe give him a few more months to adjust to the changes before giving up on him.

I'm sorry you are going through this. Communication is so important, seems like there must be an underlying problem. Others mentioned a medical issue maybe?

How does he feel about being a father? Does he want to help raise his child?

I can't offer any great advice. I hope things start to work out better for you!

That’s not an easy question to answer. Have you tried to tell him how fed up you are and that he’s getting close to losing you? Maybe he’s freaked out about the baby and doesn’t know how to communicate that to you or maybe even to himself. Maybe he’ll snap out of it once the baby arrives.

We are the only animals on earth who think of time invested as an actual investment, not to be abandoned because of what we have put into it. Forget about the six years. Think about now. If it's bad, it's bad. Think about what you want and what you're willing to put up with. There's a buy in in every relationship. Is this relationship worth the current cost to you?

What you're describing sounds like a loss of interest in putting effort into the relationship. That could reflect anything from an actual loss of interest in you, to depression, physical issues, mid life crisis, etc.

There's nothing in your post about being pregnant but a couple of people have mentioned that. If that's the case, it's particularly concerning that this is developing at a time when a couple should be drawn together in anticipating making a stable home for the child. Maybe he's freaked out for some reason about being a father and this is his way of avoiding "dealing" with it. But until he opens up about it you can only guess. If pregnancy is in the mix then my money would be on some kind of approach avoidance going on around that ... but ethically, he has to work it out. If you have to issue ultimatums to make that happen, then so be it.

Sorry you are going through this.

my approach to strained relationships has always been to call it quits rather sooner than later. in the case of my longest relationship (8 years) i actually gave it 2 more quite frustrating years after it had started to get uneasy - & in the end we managed to stay friends. someone else might stay, no matter what, "working through it together" & secretly gnashing their teeth; my experience & trust in myself is that the love within will be there anyway, & people exist like so many stars - why wreck the rest of my life in unhappiness...?

I sttrongly suspect, based on personal experience, that he Has moved on, with someone else, because the behavior you describe is Not loving, caring, or even concerned in the least with you. Sorry...consult a lawyer Now!

My ex-wife and I knew for about years before we decided to just go ahead and separate

We were together 11 years (married 8 years)

Sad to say there is a trick some men use to absolve themselves of responsibility in a failing relationship, which is simply to become such a pain in the arse that the other partner leaves or throws them out, making him the innocent victim of a heartless and unreasonable woman.

You do not want to wait until you get slapped in the face! When someone stops trying any is liable to happen.

That's difficult to say. Being In Love with someone and Loving them are two very different things. So I just hope things get better for YOU, either way.

Does the timing coincide with anything, like this site, for instance?

Unfortunately, I think you should make a clean break. When things are done, they're done..

Depends on how long you've been together. Six years is a pretty strong investment. OTOH, if you had just met him last week, then CYA. Certainly no one suddenly loses "communication skills" or ability to listen. Somthing has caused a road block that has brought out this characteristic in him that's always been there, but was not relevant to yr relationship. If you hope to save yr relationship, you need to figure out what that is, and more importantly, need to make him understand it.

He is not interested in his relationship with you . Sounds like , he's found someone who he thinks makes him feel better about himself . He has no intention of making you feel good about your relationship with him . Prepare to stand on your own two feet .