I'm in love with him and I hate it...What do I do?

I hate him so much, but I love him at the same time. I know he doesn't love me back, and that makes me mad, mainly at myself because I'm so stupid. But then he gives me this smile and whenever I'm with him he gives me this stupid sense of belonging. He'll ignore me one moment and then the next he sees me and is completely amazing. Whenever I'm with him I'm happy. I hate it. I can't be like that. I can't be in love with him because I know he'll never be in love with me. This is undeniably true. But he makes it so hard not to love him! What the hell am I supposed to do?