Hi Ashers ~ I do this too. I think for me it's because I'm not comfortable in a social setting. I don't feel adequate ~ or as up to date or as good as. I know it's all in my head, and I've been in and out of therapy all my life and I don't want to go back. I'm tired of it. lol And like Rhiannonnsmoon said, I don't like it when people just "pop in" to visit. I can't stand that. And I don't go visiting either. I'll talk on the phone or online. I'm disabled, so visiting isn't easy for me.
And I think I'm alot like you in that i've been stabbed in the back many times too - and I won't allow myself to get too close to anyone anymore for fear of that happening again. I have one VERY close friend, whom I've known since I was 4 yrs old ~ we tell each other everything. Other than that, I just have acquaintances. At this stage of my life, I don't see it changing any time soon.
Best of luck to you ~ I wish you all the luck in the world. Take care and God bless. Hugs, Lee