I can't add much to the good advice you've already gotten, but I just have to ask...if he is so wealthy, why didn't he have auto insurance? Just something about that struck me as odd?
Remember, no matter WHO it is, you cannot change a person....and always keep your standards high as to how people treat you. If he isn't open to addressing this issue (it's an issue for you, which should be an issue for him)...then you have some thinking to do.
Maybe lots of people are angry about something, but lots of others aren't. You don't have to restrict yourself to dating angry people, in case you don't happen to like being around anger.
As others above have pointed out, it may be possible for boyfriend to get help and make himself more pleasant to be around. I wouldn't waste any time on someone with that kind of anger if he won't get help that works, but that is just me. I was raised by an alcoholic and swore all my teenage years never to choose a partner with behavioural issues. I watched my mother and others live a lifetime of denial hoping something good would plop out of the sky and fix their spouse, but it never did.
Sounds like common depression to me, though many believe that's a personality disorder nowadays because of the labeling pharmaceutical companies have done with the different bipolars. There's only one true bipolar, the others are just varieties of depression. By the way, a lot of people are pissed off at rich people and corporations, always have been. The question isn't his politics or economic beliefs, but how one expresses them that matters. Passion is normal in these areas, but anger without doing anything about it such as getting involved in peaceful change isn't (unless you live in a dictatorship). Depressed people get very frustrated and angry. So do anxious people. Perhaps he should see a therapist if he's willing, though he may think he's perfectly fine, in case you have a decision to make.
You should go to the borderline personality section.:)
There is a possibility he has some kind of disorder. We can not give him a diagnosis though. I can tell you a couple of things I think may be going on. First, he needs to get in to a good Psychiatrist, which may be very hard to get him to do. To me it sounds like possible bi-polar or possible borderline personality disorder. I am not a Dr and this is just my opinion. Would it be possible for you to talk to him about seeing a Dr? It sounds like you really care about him but something is going on and if he refuses to get help this is going to be very stressful for you.