Having bipolar myself, I don't necessarily see that all that much in what you describe. Consider too that "moods"/reactions can be used to control others, making you fall into line with what he wants. (I have personally experienced this.) He does sound rather controlling and isolating. You mention things being unpredictable and that sometimes he treats you well. That may be what they call "intermittent reinforcement". You get crumbs and hope that things will get better/return to the good times that you presumably had earlier on. Was he particularly attentive when you two started out? Have you ever read any articles or books by Shahida Arabi? I would recommend them and see if the behavior resonates with you. It's behavior that I know too well, and what you describe is similar to my experience.

Wishing you the best. Being in a lonely marriage is a terrible feeling.