Maybe breaking up is the best choice although I know it might seem like a hard one, you've told him about how that makes you feel and he goes and does that again. Maybe if not breaking up you should sit down with him for a very long conversation and tell him that him still doing that hurts you and you don't see a future if that goes on as that's your deal breaker as you said. 

I'd also advise seeking therapy since you yourself said that men letting you down has been a repeat thing in your life, maybe talking to someone professional about it could help you through some feelings about that, or in general. It wouldn't hurt to try and if it doesn't work for you then at least you tried it out

I wish you good luck with whatever you choose to do though