He has a extremely short fuse, gets unbelievably angry very fast, seemed depressed a lot of the times, and doesn't think he is good enough for a lot of things and eager to show off if there is anything he can brag about. But on the surface, he is still that easy going guy.
He needs some professional help from a trauma therapist. Hopefully one that deals in male childhood sexual abuse (CSA). Pick up some books on CSA. I found my public library had about a dozen but it was sometimes hard to find them when I did a search for them. http://1in6.org/men/books-films/for-partners-spouses-etc/
Give him time. Learn what you can. Don't think that you can solve this on your own. It can be very destructive on you as well. Take care.