I think the best thing to do is just talk to people.
No offence, but maybe you have done/ said something to upset them without realising?
Or maybe they don't realise they're being rude. I sometimes am a little sensitive to peoples' comments etc and get annoyed when the person hasn't meant to hurt me... maybe it's a little the same with you?
Like Ejayrazz asked, what have they done? This might help us answer you better.
Hope you cheer up x