My bf has been cheating and Idk what to do…

So I 16(m) have been dating my ftm bf 17(m) for. 4 1/2 months, recently even me have had cheating in the past, mainly do to are diagnosed hyper sexuality. Recently they just came out to me about this one ( we both come to eachother honestly when it happens ), and they were doing it with three other dudes online… I’m in a pretty fucked up situation and I also have a lot of other disorder with abandonment and trust and anxiety…I genuinely don’t want to leave but I don’t know how to over come my own issues to to do leave physically and mentally…