Do what is best for you and the children. It doesn't sound like you can "depend" on him to be stable right now, especially if he has stopped taking his meds and appears to be getting worse. You can only live your life, can't really do much "for" him as no matter what you do and how you see it he's going to have his own perspective. Work to live your own life and help your children grow; his problems are his and it's ugly and inexcusible of him to blame you. You heard him say he doesn't like the sound of your voice and you have become quiet around him -- why should he get to control your voice and why should he say such an ugly thing? Why shouldn't he keep his negative thoughts to himself instead? You're trying, he is not, plain and simple. He's having a hard time but that's an "excuse" and there are no excuses for not trying to do the best we can.

Were he my husband I'd tell him to leave and not come back until you determine he might and he'll have to show you he's stable and working at making his life and your family life work.