<human>: Give me the gist of the text in a nutshell

And it's not something I share with people obviously, because it just makes me a horrible person.

I know the roots of this, one is having a close relationship with my cousin (7 years older) with SM, and with whom I was left alone regularly. I'm kind of socially-inept to these days, but back then I was even worse, and I just couldn't handle him, he was on the mental level of a 13 year-old horny boy, and always made me feel really uncomfortable, and I was told to just bear with him, and to be cool and nice.

My other experiences with people with disabilities come from traveling to school on a route between a clinic and a hospital, and I was often harassed, followed all the way home, and these people were usually visibly mentally and/or physically disabled.

I know that I can't just put every person with some kind of disability in a big box, and think that they are really really different people, each and every one of them, as every condition is very different. But I can't help but feel extremely anxious when I see signs of disability on a new acquaintance, it just puts me in "alarmed" mode, I can't look them in the eyes, and just want to get away from them, and I don't pursue the relationship any further. One of my closest friends started a relationship with a girl with cerebral palsy, and I voluntarily exited his life for 2 months now, because I feel like panicking around her (I want to literally run away from the group).

And I guess it is exactly as it sounds : I don't see the person, I only see the disability. But I don't know what to do, my body tenses up, my mind shuts down, and I feel like crying when I'm around her. 

I don't know what to do. I want to befriend this girl, but even if I get less tense after a while, the first sign reminding me of her condition I close back up, and try to excuse myself for a while.
<bot>: I can't see the person behind the disability after having some bad experiences in my childhood. One of my friends is in a relationship with a girl with cerebral palsy.