Should I leave this guy alone?

This guy use to like me and I liked him abit, but I didn't really make an effort and he did. But then when I started to like him, i made the effort and he didnt. I told him that I liked him and he said same but after that he was being so ignorant. I asked him to play out with he just shrugged. When he use to like me, he never asked me to hang out with him or anything. So I'm making more effort with him. He told me a week ago, he went out with someone. And I see him all over facebook telling girls how 'hot' or 'fit' they look. But the past two-three months he has been really cocky and I think thats due to him getting kinda popular with the girls. I kinda asked/hinted that I wanted to go prom with him and he shrugged. I found out that he asked someone else out, that really broke my heart. But I'am really confused, he hugs me and says he loves me sometimes but he mostly doesnt. Should I leave him alone and why is he doing this?