Most Helpful Guy
I think your gut feeling is right. With the description of things up to now, I don't see it being any other kind of break up than he cheated and felt guilty. If it was all about him, then he couldn't trust you enough to list off some of the problems he's facing and feels compelled to leave? No -- its because he can't because he screwed up.*
He'll have to lose you to understand what he gave up; not every guy of course, most of us can appreciate what we have enough to not cheat without having to lose it. He may go his whole life and never find another girl like you.
I'm sorry you are going through this, and you didn't even do anything wrong.
* = probably.