1. Be honest with him, communicate your needs, thoughts and desires. No matter what he is dealing with, he is not a mind reader.
2. Be prepared for the worst and the best. Yes, he may choose to leave when you confront him with what you need and what isn't working but, he might not and, may get the help he needs.
3. Get help for you, no matter what he does you need a support network too.
Dealing with us (survivors) is not always easy. We have our insecurities, or moods and, our quirks, not to mention more serious issues. Still, don't treat us like we are fragile and might break - we are broken, you can't break what's already broken.
Despite what we endured, we are men and, we are not mind readers, we do want to be good for out families. We might not know how or, see what we are dong wrong, but you can tell us so we can decide how we want to handle the issues we are causing.
As for when the turning point it, when we seek help - usually about the time we hit rock bottom. That's just male behavior - we will try to go it alone as long as we can.