From everything you've written here is sounds like he was indeed manic. The mania made him see you and others as threats. He was very scared and it was very real for him. My heart breaks for him because I know this pain all too well and suffer from nearly identical thinking patterns when I'm in an episode.

With that said and out of the way....you have done NOTHING wrong. You were a good girlfriend and supported him when others would have ran away in terror. He should be thanking you but it sounds like his perceptions still aren't right. And some people cannot apologize. I know many people who simply cannot do it. Some people cannot even see when they are wrong unfortunately.

I go through manic/delusional episodes very similar to yours. My husband is a trained mental health professional and his mother has bipolar....so he is very understanding of my illness. But my illness does hurt him. Last time I was delusional, my husband cried for days repeating "I just want my wife back". It was so very hard on him. Not everyone can be there for someone who is truly mentally ill and I don't blame them. You need to do what is right for you. If you decide to end this relationship, it would be understandable and courageous. You need to take care of and protect yourself. But if you think you have what it takes to stand by this person and love and support them for a committed lifetime, then I admire your courage, strength, ability for unconditional love. You have my support no matter what you decide. (((Hugs)))