Is it possible to get back trust?

Ella
About 6 months ago my boyfriend cheated on me, it was just a kiss but it was with one of my friends. Not that it makes it any better but my friend is mental, and was cheating on her boyfriend at the time with about 4 different guys, we're not really friends now but for lots of reasons not just because she kissed my boyfriend. But yeah, he didn't tell me for about 2 months and one night we were drinking and I said to him 'I feel like you've done something questionable' right then he broke down crying and came clean about it... 
So obviously that broke my heart, he told me he was having some doubts about our relationship at the time but as soon as he actually cheated he knew it was me he wanted to be with. Ever since he told me he has been amazing and honestly treated me like a princess, and I do believe it's not just the guilt and that our relationship is genuinely stronger. 
We have mostly the same group of friends so we hardly ever go out without each other but on the rare occasion he goes out without me I do worry a bit that he'll cheat. I guess I don't know if that's an understandable thing or if it's a complete lack of trust. Before the whole cheating thing came out I honestly never considered he would be unfaithful and o trusted him 100% 
I want to be with him and I know he wants to be with me, we're pretty much inseparable and have such a good relationship, the only problem is when he goes out I do worry still that he'll cheat. Has anyone else been in a similar situation? Do you think I'll ever stop feeling this way? Please don't give me grief for staying with him after he cheated because it was a hard decision but I believe it was the right one...