Hey Angel!
I know how you feel. I've always been real easy going and accepting of people, but the last year or so I tend to get very angry, very easily! It really bothers me because I don't want to be angry or hateful. I'm trying to work on this and get back to trying to understand a situation or person before I react though. It's hard sometimes, but I think it's worth it.
Anyways, I just wanted tell you that I understand your anger and frustrations - it's completely normal when you have to deal with so much internally every day. Try not to let it devour you though. Notice the little things that make life worthwhile - it will help you relax and help you keep going. For me, the little things that remind me that the world is worthwhile are things like the shapes of clouds, spring flowers, bugs on the sidewalk, children laughing, the wind blowing..... yes, I'm a cornball. ;p Find the little things that made you happy once and try to remember to stop and notice them even if just once or twice a day. It helps me - I hope it will help you, too!
But also remember, it's ok to get angry once in awhile - it's a natural emotion that you are entitled to. Just don't let it devour you so you lose sight of what's important.