DH has bipolar I. No family history, had his first episode completely out of the blue 15 years ago. We've stayed together and have 3 DCs. He's a lovely guy and has a good relationship with the DCs but I don't think he's ever accepted that this is a lifelong illness. He has long spells without episodes (years) but gets uptight about me checking how he is and then he comes off his meds without telling me and sooner or later he gets manic and psychotic and it's horrendous.
He did it again last year. I had to grab the kids and go.
He has moved out to give us space to work out what to do. I feel trapped. If he comes back I think it will happen again. But if we split up his mental health will likely get worse.