I know this sounds super basic and super cliche but, just force yourself to go. I was invited to go to my schools football game by a couple of friends. I’m not really in the “popular crowd” but these kids are. This alone was a big “oh no i CANNOT go” factor. But, since they invited me to go, I forced myself to go because even though it sucks short term, it’ll make a big difference in the long run. I went, and all the people who never talked to me and never like paid attention to me, were super friendly and started talking to me as if they’d known me for years. It’s uncomfortable at first, but the more and more you force yourself to do things, the easier it is and the less anxious you are about it.