If you honestly want to grow and overcome your issues, now is the perfect time. Use these days while he is away to look in to counseling, go check out some self help books, do whatever it is you need to start actively working past your issues. Let him know what you're doing in a matter of fact way (not in an emotionally manipulative way)- "I've realized that my trust issues are really a problem for me and I don't want that. I've decided to work on that, I've taken these steps so far." It's easier to forgive somebody who makes understandable mistakes if they show a real commitment to growth and are making efforts to not make those mistakes again. It's up to him to decide if that's something he comfortable with. Either way things go, actively working on your trust issues will only make your life better, in this relationship or in any others, so it's a wise decision to make.
That all being said, I think "setting you up" to prove a point is kind of douche-y, especially if that point is being used as the excuse to end things. Even the most trusting of people would probably question things in that scenario. I would question myself if that kind of emotional manipulation towards me was okay from a partner, and I would at the very least have a discussion with them about it. Just saying, because you might have messed up, but so did he.