BOYFRIEND HAS OF ACC

so I recently found out that my boyfriend has an onlyfans account and has subscribed to 3 accounts. He doesn’t know that I know, but what do I do? I don’t know how to feel about it. I feel like it’s classified as cheating but I just don’t know. I feel upset and hurt because why would he feel the need to pay money for nudes when he has me? It makes me feel like I’m not good enough and he has to pay to watch other girls to get off too. I want to confront him about it, but don’t know what to say because if I say I went through his phone he will get hella mad and it will make our relationship go to shit again after it just becoming good. Please help!