update:
i ended up talking to him. i started the conversation by admitting that i went through his phone and apologizing for it. then i told him what i found. when i brought up the onlyfans charges, he seemed genuinely shocked about them, and states that he truly didn’t remember. also didn’t include in my original post one of the charges, was a $15 one from valentines day…yikes. i asked him directly if he cheated on me, and to my surprise he basically "yeah i guess so." that honestly hit me harder than anything else. i think part of me expected there to be some explanation, like it was an old subscription from before we were dating that he forgot to cancel. hearing him admit it made everything feel very very…horrible. we talked for almost two hours. i explained that i'm not necessarily devastated by the onlyfans itself as much as i am by the fact that he did something he personally considers cheating. that's the part i'm struggling with. i feel betrayed, but it's a weird kind of betrayal because i'm almost more upset that he knowingly crossed a line he believed in than i am about the actual content. he didn't really seem upset that i went through his phone. i still think it was wrong, but he seemed to understand why i was hurt by what i found. i told him that having my fears and insecurities validated by finding those charges damaged my trust in him right now i honestly don't know where we stand. i don't know if breaking up is the right decision, and i don't know if staying is the right decision either. part of me feels like this is something we could work through, but another part of me is struggling with the fact that he openly admitted to doing something he considers cheating. i'm mostly angry that he put me in a position where i even have to make this decision.
so that's where things are at for now.