"That one strange feeling"

I was good at studies since the school days. I was lauded girl having no issues with anyone. I had good friends and could share anything with them. The same thing is in college with me. But a strange feeling of being excluded from everything and everyone without being so comes. This makes me to stay away from people and I don't pretend it to anyone. No one knows either I am angry or sad until and unless I clearly state it. I have no issues with anyone and people are kind to me. But I feel strange to them... I weep deep inside me and this feeling does't make me happy. I feel I am worthless. When out with friends, I seem to be the jolliest person but the loneliest from inside... I am so bad at sharing my thoughts with people...Whatever I do I just feel that I shouldn't have done that...When I say something...they feel I am a source of happiness for them...and after talking to them I feel like I am just an empty pot...nothing to give to anyone...I feel like giving up...I don't know why but I am tired of pretending talented, happy, caring...I just want to stay away from everything...I want to sleep with a calm and peaceful mind...