Mean boyfriend

So lately my boyfriend has been mean and a little bit more irritable and stressed out lately. He’s been mean to me and he been saying some of his coworkers are getting under his skin lately. Idk what’s wrong with him. Last time we talked he just came out and told that “The reason I’ve been irritated lately is because I am sexually frustrated.” We haven’t had sex yet he both want to because we are extremely horny. But there has to be something besides sex. Idk maybe it’s something deeper.