Is this anxiety or just being shy?

okaaaay so this probably might sound like im being dramatic but u know i might as well ask anyway. Alright so lets say i have to go to a party or something, if i get really nervous and tense when someone comes up to me, even someone i already know, is that just normal antisocial things? Also like in school when teachers say get partnered up, i get that some kids are sad cuz they dont have many friends, but is it normal for you to be so anxious that you go to the bathroom and do your work in there alone.....
I'm really not sure because it could be brought up as just being shy but I wanted to get some of your guys opinions.