I feel weird texting/talking to him...almost like it's wrong?

So theirs this guy I met online and we pretty much hit it off instantly. We have lots of stuff in common, and we ended up becoming good friends because of it. So now all of a sudden he comes out and says he likes me, however I do not feel the same way about him since I really don't want to be in any kind of relationship with anyone right now (still recovering from a previous breakup, and want to do some soul-searching before I go there again). Long story short, he starts dating this other guy however still feels the same way about me. He is CONSTANTLY telling me/texting me about how unhappy he is with his new guy and wants to be with me, even though he knows I do not want to go there with him. What do I do? One of my other friends tells me that our friendship is doomed to fail because of this, and I don't want that to happen. What should I do? I'm debating whether or not to just stop all communication with him until he forgets about me one of my friends says that ignoring him for a while is the best way. Advice please!