My boyfriend thinks I’m cheating

So recently my boyfriend and I have been arguing a lot lately which means we haven’t done anything sexually. Which makes him think I’m cheating on him. Sometimes I’m just not in the mood and he feels that im cheating on just because of that! I asked him why he always assumes I’m cheating and he said because this is around the time chicks start to cheat. Mind you we’ve been dating since November of last year. Me being fed up with the bs I tell him the only reason you ask me if I’m cheating is because your cheating and then he gives me a look like I’m tripping but I’m not. I’m not stupid. If someone is accusing you of cheating then that means that person is cheating as well. I don’t know what to do.