I'm sorry to hear about what you're dealing with right now... It's so easy to be angry at the world when one is faced with the kind of issues you are, you know?
One of the things we know about anger is that if we don't find a way to let it out naturally, when we feel angry, we think we have things under control by bottling it up and suppressing it. But we don't. All that happens is that we blow up at other people, for no reason. Sometimes even complete strangers.
I suggest reading the below article, which may help, and find other ways to help express you anger more as you are feeling it (and not keeping it all inside). Find an online cancer support group as well, because if you find this kind of community helpful, such a group would also likely be beneficial to you.
http://psychcentral.com/lib/2007/tak...of-your-anger/
Take care of yourself and remember that you're not alone in what you're dealing with (although it may often feel like that).
Best,
DocJohn