There are multiple types of bipolar disorder with various features, so take any advice from strangers with a grain of salt, as they probably don't know the specifics. I have a couple of personal experiences with bipolar disorder in general.

First, a close friend of mine - his manic episodes would usually involve him staying awake for days at a time, and his depressive episodes were pretty bad. Before being diagnosed with bipolar disorder he had some pretty bad experiences with therapy from a "therapist" that clearly didn't know anything about depression or bipolar disorder, since being diagnosed and settling on a medication he has been much, much more stable. I used to lie awake unable to sleep from the stress of worrying about him, I don't anymore. He still has depressive and manic periods but they are much, much less severe.

Secondly, an aunt. She had one of the more severe types, but we didn't know it. She always had bad depressive episodes (and there was apparently an early bad episode of mania that was written off as a one-off mental episode from stress or something) but it wasn't until she suddenly left my uncle and their children to run off with a married man she barely knew that it became more apparent something else was wrong. I suggested - stressing that I am not an expert in the matter - that it kind of sounded a lot like some of the self-destructive manic episodes I had heard about, not from my friend but from Stephen Fry. I had heard him talk about his bipolar disorder at one of his shows in Sydney, and his past involved a lot more trouble than you'd expect. He has a couple of documentaries about it, but I can't speak on how helpful they would be. Anyway, I turned out to be right, and so far she seems to be doing better, but it's still early days.

The main takeaway is there is hope. One thing I took away from Stephen Fry's talks in particular was that it is vital to keep taking the medication and not to decide, after a period of stability, that you don't need it anymore, that's a recipe for disaster.