(The following is a response to a private question.)

Among others, one of the things I consider a black flag —something that’s more than worrisome, and simply disqualifying— is the suicide-threat control tactic. It’s gross from anyone, but when the person in control of a relationship is reduced to that shit, they’re showing you that they’re dangling by a thread. They’re weaker than you in every way, and they know it. For you, respect has become fear has become pity.

Once you accept that, you’ll see it’s been over for a while.