Does anyone else feel "wrong" when out&about?

It's just this feeling I get when I'm out (mostly by myself) and there's plenty of people in the street. I feel like I shouldn't be there, like I'm the ugliest and weirdest mo-fo to ever walk the earth (okay, slight exaggeration there, but you get the idea).

I feel so out of place and I get very nervous just for being out in the open (if that makes any sense).

I've always thought it might be some kind of social anxiety issue but I seriously don't know what this is.

I thought it'd get better with age but I just can't seem to shake it off and it's so annoying.

Can anyone relate at all? I don't know how to get past this.