I'm going to cut off an autistic guy for being too clingy
Why would you cut him off?
I can't handle having any kind of physical contact with him.
I get your point, but its not nice to avoid people with developmental issues. You might hurt his feelings, but you may need to set boundaries if you feel that uncomfortable.
He knows I'm uncomfortable and needs a lot of contact. I think he's doing it on purpose.
You have the right to feel comfortable if others do not respect you. Having a disability is no excuse for violating normal interactions.