Is this guy using me? or does he actually like me?

I think he had interest in you that has not grown to meet your level of interest. You want a relationship. You see him as a good person. He has not gotten past the initial attraction. Your beauty, your physical assets. But, he is losing interest now, because you haven't let him get to what is the end of physical attraction, getting physical. My guess is there are better fish in the sea, throw him back for a keeper. Your other choice is to step things up physically and that sounds contrary to your goals.