OK, first off, this is NOT your fault! He needs you to be the "reason" for the incident because if he's the source of the problem, he might have to dig a little deeper to what's really making him hurt. Maybe he feels inadequate now that you're achieving your dreams because he isn't? The main thing is, there is some deeper issue that hurt him enough to go to someone else than you getting a degree and a great job.
Maybe my husband could tell you better how to deal with the anger since I was the unfaithful wife, but here's my take: let go of the anger for YOUR sake, rather than his. Your anger hurts you probably even more than him. When you feel that pressure start to build try to step back and say, "I value my own sanity.I will not destroy myself with bitterness." it sounds silly and simplistic, but try it. Say it aloud if you can. Sometimes just hearing the words can make you realize it takes way too much out of you to be angry all the time.
The grass may be greener, but then again, it may also be astroturf. ~Amy C Brown