You may be over anylising...but that means you care. Life is full of doubts and indecision..sometimes you need to ask what have I got to lose..or what's the worst that can happen. But if you are genuinely not ready..say so..they will hang around if they are worth it..if not ..so what..you've lost nothing.

Well if it is a Jenny Taylor problem you can try a hearing aid (read my post in "Cheesy Jokes" today). ?

Depends on the circumstances, of which you are not willing to disclose. You might have a good reason to not trust this person. We don't know though.

Emotions don't lie. Something triggered you.

You're in unfamiliar territory. That can be good or bad. It's bad in the sense that you're not always confident; it's good in that always being confident is often seen as cockiness. There are nuances which you don't recognize, etc. Be genuine, true to yourself. From our interactions you seem a positive, worthwhile person. Happiness!

Something said may have hit a hidden trigger you didn't know about. If you consider the other person important, explain to them what happened and why.
Memory is a tricky thing and the right combination of stimuli may have triggered a subconscious reaction. Then again I'm not a doctor nor do I play one on TV.

Check if you can compromise and if it really makes a difference in the relationship.

Sounds like my early days back in the dating pool. We are all a product of our experiences, and something hit a trigger or pain point for you, even if subconsciously. Be patient with yourself, and talk to the person. Grownups talk through these things. I had a situation early on (over 3 years ago) where my insecurities got the better of me. The relationship ultimately did not go anywhere, but the talk was priceless and a growth experience. Hang in there!

Well. That's vague.
So, say what you mean and mean what you say is something I go by generally.
.
Your dilemma - said things may trigger emotional reaction from your bag of tricks, or the someone else's. You answered yourself realky, maybe you got things to work out.

Talk to the person about your reaction and insecurities. Open communication is a good thing. Getting into a relationship can be scary, and it may dredge up some old issues, but that does not mean you can't go for one. Be honest about your needs, anxieties, and desires.

"Do I not trust this person?" or you don't trust the situation. Or simply you are checkin the limits.

go slow. trust your gut. don't let anyone try to make something of it that it is not, regardless of what you want.

My approach would be to first evaluate the significance of the issue, try to decide what outcome would be preferable according to what path I chose, then go from there. That's about the best I can do with the info given.

We all have those doubts, I think, from time to time. I've found that as I age I become less and less inclined to engage if/when it seems to me things may get very complicated, and there is a chance of great disappointment and/or broken expectation. That said, I try to counter those thoughts knowing that can lead to isolation and loneliness if not checked.

GASP
You are a human being!!!
We ALL make mistakes, and have over-reactions to things we often later regret.
It's okay. Cut yourself some slack.
If this potential relationship is meant to happen, you and the other individual will
talk it out and move forward.
Don't sweat it, sweetie!

Don’t judge youself harshly, talk to them... none of us are children and we all have baggage. You know I believe in meditation, it’s somthing I do to try and recognize my own triggers before they happen... with mixed success. We never stop being human

I don't care how grown up people get - there are always some things that can get us going.

Recognizing that it happens and looking for why? Yup. That's what you have to do.

It can be as simple as a phrase someone you detested used to use. Or be way more complicated.

I've found that taking a step back and going and looking at the conversation again can be helpful.

Without more information, it's difficult to provide any meaningful feedback. I suggest you answer your own questions above. You know you best. =]