Mrs Conceited

I have never in my life met anybody as conceited as I am. It sucks, and I don't know how to change it.
It has nothing to do with my appearance, in fact, I believe I'm a very average looking person, HOWEVER I always assume that certain situations are about me. Me, me, me...
For example, someone (even someone I haven't actually seen or spoken to for months) will post a random comment on facebook and I will automatically assume the post has something to do with me and that the person is subtly trying to send me a message. Especially if it is something bad. I always assume people think the worst of me and as mentioned in my previous post, are conspiring against me.
I believe that people close to me has heard rumors, and instead of asking me about it, they just believe the rumors and try to "get back at me". Aarrgg.. frustration is not the word.
I try my best to be nice to everyone I meet and talk to. Because of that, I think that people might think I am too nice, and then they don't trust me without realizing that there's nothing more to it than me just wanting everybody to be happy.. it's quite sad, actually.
Today at work, one of my colleagues were talking to a lady (I didn't know at that stage that it was her mother), and telling her something like " apparently the guy treated her like shit" and they were laughing etc. and I thought they were talking about me, because my previous boss treated me and my ex-colleagues badly, and that they don't believe me and are trying to scheme behind my back. It's crazy. I don't even think this specific colleague even knows about my previous job situation...
I try my best to always be honest, yet I still believe that people think I am a liar.
I try my best to be loyal, yet I still believe that people think I am a snake.
I try my best to be friendly, yet I still believe that people think I am fake...
You get the message?

Anyway, to end off, count the number of I's and me's in this post, and you will see what I mean...