I'm like this too, try to remind yourself that they are no longer in your space.

When people get in my space, and before I got my service dog I would try to step back from people when they were almost to close. This helps sometimes. With Bently now( service dog) he creates a bigger personal space for me. He gets in between me and others and unless I move him, they can't get in my bubble.

For me, sometimes i need physical space but often its just not being able to spend too much time with people and needing to retreat to my own space

I can't deal with people anymore without getting all wound up and hyper. I find that life is much better for me if I just stay home and work on my urban homesteading project.

Just talking on the phone with my brother-in-law today got me so wound up that I was almost shaking. But I suppose part of that was him, he tends to be very excitable and yells a lot. He's always been that way.

Doctors particularly get under my skin that way...since after all they do literally get under your skin. I take weeks sometimes to settle down after a doctor's appointment, especially if it did not go well.

I thought for years my difficulty in dealing with people was because of my ME/CFS. But one day I remembered that I've always had problems with feeling threatened by people. I had just gotten so used to being this way that I thought it was some kind of personality trait. Now I think ptsd is a much more likely explanation.