Words,actions,not as affectionate, hand holding is reduced,quick to anger,little thing are an irritant....

If you're asking the question, the answer is now.

It seems like the answer should be drop-dead obvious, but the truth is that when you are in a relationship you inherently aren't objective. It's the main reason it's considered wrong for doctors to treat their own family members. But in a relationship you are the one making the decisions and no one else can do it for you.

The more practical question often is, when do you let go of what you thought was a rare gift: the kind regard and loving attention of another person? You are generally in the midst of a sunk cost fallacy. You've told yourself, and maybe others, that this is The One. You're heavily invested. And now you must take the heavy emotional toll of grieving a great loss, akin to but in some ways worse than the person dying.

To me the best antidote to all this is to let go of romanticism, the 12th century notion that there IS "The One" who will in some mysterious way complete you. Do not trust your feelings of transcendence early in a relationship. Enjoy them, but don't trust them. Instead, make sure you always have yourself. That is, be good enough to yourself, affirming enough, kind enough, respectful enough, that having those things from someone else is merely "nice to have" rather than a draft of cold water to someone dying of thirst. Have enough interest in life on your own that sharing it in that way with someone is merely "nice to have" rather than transforming life into something meaningful.

Committed relationships generally tend to magnify what you already have. If you are already content and centered, you'll feel more so. If you're unhappy and alienated, adding a relationship will make you more so.

With these suggested changes, it's easier to recognize that a person is toxic or unreliable or otherwise of poor character, because the contrast between how you felt before you got involved with them, and how you feel WHEN involved with them, is much clearer. It isn't just moving pain and deprivation around. It's ADDING it.

When someone belatedly exits an abusive or disrespectful relationship, I always suggest that they work for a minimum of a couple of years on themselves before opening themselves up to someone new in their lives. Done right, it improves your selection skills by at least an order of magnitude.