Sadly, it is likely that he will be hurt no matter how you leave him. He sounds like a guy who is so wrapped up in his own enjoyment and needs that he is not considering that you may have some needs also.

Talking to him will be hard but it is the first step. With luck he will listen to what you say and try to change. If not, you can at least leave knowing you did all you could to save the relationship.

Good luck whatever you do. We are all supporting you. Let us know what happens.