I've always tried to do my best to socialize with people, especially my classmates. Yet, it doesn't matter what I do, they don't seem to like me

I don't understand. Why don't they like me? Why do they ignore me? What is different in me that makes them dislike me? I don't really act any different from how they behave... so what is it?

It's just so frustrating.. I'm afraid I'll be alone for the rest of my life..