Why do some old friends ignore you after high school?

I really don’t understand. I joined three friend groups but it didn’t last. Middle school they stopped talking to me because I’m too awkward, rude and they didn’t ask me to hang out anymore. High school wasn’t great either. Some peers let me hang with them but later on they stop talking to me. I texted and texted and asked them what have I done. Or if I did or said something I apologize. I have up. College same thing happens. After two years, we all split up. None of them speak or me anymore. They decided that I am too much for them, i looked mean and put off by my differences. 29, no friends. Im just going to stick being friendless and single. My NT ex boyfriend cheated on me with an NT woman because he thought I was using autism as an excuse. Had so many fights. What is wrong with me?

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7 mo
I’m autistic
Why do some old friends ignore you after high school?
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