How do I deal with this?! ADVICE WANTED!!

Portia
Ok. My boyfriend and I have been staying together until we move into our own seperate apartments come August. We've been arguing alot also for awhile. Despite the arguments though, we truly do love each other and we want to work and smooth things out when it comes to us. It's been hard to do that. Anyways the other day, he and I got into a heated argument and in the midst of it, I told him I went through his email the other day. (First time snooping) Now, if it's one thing we value as a couple, it's trust. He was really angry and hurt by it and now he feels like he can't trust me right now. 😔 I understand how important trust is and I know i slipped up and I'm for sure that I wouldn't do it again. He decided to move out earlier today to his friends house because he just needed some space and I can understand that due to the fact we've been at each others necks AND i decided to read his emails. I feel like we're really on the edge right now. I just need some advice on how to deal with the space thing and how to reassure him that I would never betray his trust again. Help! Any positive advice is great advice!!