Believe it or not, avoidance is the worst thing you can do for anxiety. The more you avoid situations, the worse your anxiety will get, and the more help you will need to break out of it. Instead, acknowledge the feeling to yourself. Tell yourself "I'm feeling anxious right now, and that's okay". Allow yourself not to feel like the best, shiniest version of you right now. Smile or nod at people to show some respect and then carry on. You don't have to stay and talk to them, just try not to be rude to them. Good luck.
what is the cause of anxiety and stay around good people who elevate your mood
the disturbing thoughts that they are not my true friend and they will never understand me
Okay, so what proof do you have that that statement is not true? Have they supported you before?