Husband has anger issues

I've been with my husband for 15 yrs. Since high school. He's always suffered with anger. Let me start of with he has never touched me or hurt me in any way. I'm being very honest in this post so there is no reason to lie because it won't help me or him in the long run. So most of the time I noticed the anger came from video games. So I figured oh goodness he's one of those guys. I continued dating him because it wasn't towards me and he's seriously amazing! Funny, sweet, and makes me happy for the most part. We've only had sex with eachother. No cheating in our relationship. We mesh very well with our views. Well the only issue is his anger sometimes. For one when he's mad he breaks things. Also, I know when its coming he gets in these wierd mood. First he feels more sleepy than usual. Then agitation, then he starts staying up late, next his patience is really short. He kinda isolates him self. If something sets him off he will punch himself or break something. This is not every day I notice its like 3 good weeks then a couple of bad days. I talk to him and he know and he hates himself (his words). He said he feels like it is uncontrollable and he hates himself. He doesn't understand why he's like this. I have asked about therapist but he comes from a family who don't believe in and unfortunately has raised him to believe as well. Now the only thing is now that I'm aware of a pattern of behavior could he be bipolar? I know he has adhd as a child he was diagnosed is that part of this? I just want to know if this may be an actual condition or is he just has anger out burst. I'm trying to ease a way of getting him help. Why now you say well honestly and sadly on my part I never noticed the pattern until now that I don't work and stay home for the last 2 yrs. I really thought he was just upset over video games. I now know there is more going on. Anyone have an ideas or know more possibly.