just dianoised with bipolor and dual personality

Oh my, you've really taken on a lot; a boyfriend with more than one personality isn't going to be easy to cope with. The first best thing you can do is to learn absolutely everything there is to know about his disorder. You're also going to have to learn how to deal with his differing personalities (how different are they, and how separate?). It's the only way you have any hope of really understanding him and what he's experiencing--and that is not only the key to helping him, but also to the relationship.