If there are repeated crises, then it is not being managed. If they did not reveal the mental health diagnosis prior to your marriage, then they were not honest with you. If it was diagnosed after marriage, then you need to examine the promises/vow you made at that time.
An 'annulment' is a religious thing, not a civil-legal issue. An annulment is a religious statement that a fair marriage never took place, since one partner was not fully informed about the other partner's issues.
In my theology of marriage, I made a vow that I say 'yes' to each and every day that I wake up. And that vow is to stay faithful no matter what the health of my partner. Difficult? Of course. Impossible to do? No.