i have social problems i don't know where it came from?

[thatdude]

my sisters and brother are normal and in relationships and socialize but me no i stay alone most of the time. I use to be normal but something went wrong down the line i really don;t know so i'm use to being alnoe or hanging out with one friend.. I only had 1 girlfriend in my life and i was stressed the whole time with her and eventually i broke it off. I feel stressed around people like i can't be myself. It is hard to sleep or eat around a lot of people and i only feel truly comfortable when i'm by myself.. any advice or who can relate?