Don't do it. The easiest but harshest way would be to tell him that you found someone else. Since he has feelings for you, he would be upset and distance himself. Or, similarly, you could tell him your honest feelings that you don't want to end up with him and that you don't love him. Trust me, when things like taking breaks and negative feelings start in the beginning, they only get worse overtime. Sure, there is counseling and all that, but from my knowledge, they end eventually, sooner rather than later. There's a saying, All is fair in love and war. I think it's true. You have to do what is right for yourself, first. Otherwise, you'll do what is right for him, for the time being, and then you'll grow bitter and be unfair to yourself, and later to him because your feelings will hurt the relationship and he will get unhappy. That's all I can think of.
Good. It sounds like you know what needs to be done. Good luck with everything. Always do what results in the least regret.
Tell him the truth on his face. Don't keep him living up on expectations from this relation ship.
He might be crushed for few days, but it will be good for him after those days, he will learn how to handle this kind of situations.
so please please please go and tell him what u feel right on his face. It will be good for both of you.