Alcoholism, drug abuse, relationships abuse are not symptoms of bipolar disorder.
I know, because I AM bipolar and I had a boyfriend just like yours who was NOT bipolar.
Your boyfriend is screwing up his brain cells with alcohol & drugs while a bipolar person has a real imbalance that they are born with and which is triggered at some point.
Anger can be caused by childhood abuse, borderline personality disorder, alcohol, drugs, intermittant rage disorder and a host of other things. Until he is off the alcohol & drugs there is absolutely NOTHING you can do to change things - only HE can make that decision.
You may want to look into alAnon meetings or narcAnon meetings for support - but until he's sober & off drugs he will drag you down. Tell him you'll be there a year from the day that he stops doing this stuff to his body. And pat yourself on the back for moving out - that was my first step to a real life....
(By the way, I did keep in touch with him over the following years... he died a month ago at age 48 from damage to his heart from the drugs...)