Trusting my bf again

Me and my bf were both very new to relationships and when we got together it was very rough to begin with and throughout really. He cheated on me about a year into our relationship and did everything you could really imagine when it comes down to cheating, and it literally broke me. So we split up for 8 months and only spoke maybe once throughout the whole breakup. This gave us a lot of time and then after this long period, we started messaging again and soon realised neither of us wanted to be seperate and missed eachotehr a lot and after a lot of work we got back together. We’ve now been together since January and everything has been perfect but the issue of trust has got in the way a lot and is now coming to the point we may breakup again.

He goes out a lot with his mates and goes to fields and ‘chills’ there with them, he most of the time smokes which I am so against and that also gets us into a lot of arguemnts. Anyways whenever he goes out I usually check his snapchat location and when this isn’t accessible I start to panick and really worry and convince myself that he’s not where he says he is and is cheating. I also then question him a lot and make him tell me where he is and what’s he’s doing. This makes him feel trapped and chlostophobic and he says he feels like he has a second mum. He also to add, has been very reassuring and is very loving and acts like a compleatly different person since we’ve been together again. But when it comes to him going out and I can’t get the reassurance that he’s not doing something shady, I breakdown and I just can’t trust him. I don’t know what to do because he said he can’t carry on if I don’t begin to trust him again as all the questioning and worrying and me not believing what he’s telling me is making him feel awful. Please help if you have any advice, I don’t want to breakup because everything else in our relationship since being back together has been so different and literally perfect and I feel so in love with him, it just seems like I’m the problem now and I don’t know how to fix this problme of trusting him and I don’t know if it is fixable at all?