He sounds like a great guy. But your heart has to be fully into it. I think either you have chemistry, or you don't. That's not to say relationships that turn sour (yours hasn't - I'm referring to long term relationships) - couples can't put in steps to rebuild the "spark". But it does take time. I'm not sure if this will be the case with you though if you've never felt that.

In fairness to him, if you 150% believe this is going nowhere, best to just let this relationship be.