I wouldn't assume that this behavior is due to him having bipolar disorder. Having bipolar tendencies doesn't automatically make someone a complete jerk. He may have less control when he gets into an amped up state, but there is some other origin to his behavior than the onset of a manic episode. It would help you greatly to discover what that is. Look to how he grew up. What were his parents like? How did they treat him? People who rage like he does are expressing their own sense of powerlessness. He sounds totally pathetic.

Are you ever able to have any kind of an actual conversation with him? You might think you wouldn't even want to. But there's a story behind his behavior. You'ld learn a lot by finding out what that story is.

I'm not saying you should look for ways to excuse the inexcusable. I'm saying you might want to try and figure out how he developed into who he is. No one just suddenly becomes a certain way.

You will feel less powerless when you understand what forces operate on your father's mind. He is the one who let himself become powerless in the face of some adversity that he faced growing up.