Sometimes I would actually sit with the principle at my high school during lunch...she would tell me that she also had anxiety and her first day of work she was crying in her car and couldn't leave it for 30 minutes. So we shared a bond of anxiety lol and she told me that if I was ever feeling that way I could come eat lunch in her office.

You can reach out to teachers to help you or you could reach out to your fellow students. Find other students who are sitting mostly alone, go up to them, strike up any conversation, tell them you're kinda new, and ask them if you can sit with them. If you do that every day, you'll start making friends.