cheating.advice

So me and my boyfriend have been seeing each other for about 3 yrs. A couple months ago he was really depressed with his life. We would talk about how he felt like his life was just work and sleep and how he had 0 time for himself. Our relationship suffered alot. We would go a full week without seeing each other and he said he was fine with it. Come to find out this is the exact time he cheated. When I found out he was quick to admit. He didn't try to cover it up. He told me he drank a lot at a party one night and made out with one of the girls there. He owned up to his actions and I sensed he was being sincere. He said he was in a bad place and doesn't know what he was thinking. Going on the say it made him realize what he wanted in life. The way I see it is I'm glad he was able to man up to it but where does that leave us.. We're both to blame for that rough time we were going through but while I was fighting with him trying to fix things he was pulling away and went and did what he did. He accepts the fact that he fucked up and told me to take 2 weeks to think of what I wanted to do but I'm completely lost. I've always said I'd leave if I ever got cheated on but I would hate to see our relationship fail after all we've been through. I love him but also need him to respect me. How am I supposed to trust that it was only one time. And how am I supposed to trust it won't happen again. I feel embrassed, insecure, angry, hurt and confused... Any advice ?