I really can relate to so much of this. Especially the part where you describe how your anxiety doesn't respond to rational thoughts (like, I'm with people who love me and they'll look out for me). It's so frustrating when we know intellectually that we don't need to worry, yet we still experience a lot of unpleasant physical feelings of anxiety.

I do think therapy can be helpful, but definitely it's important to find someone who you "click with". And that can sometimes take a while and I know that's discouraging too.

I hope it helps a bit to share experiences here, and I hope we can offer you some encouragement. The other thing I've often found is that, sometimes, the thought of doing something is worse than actually doing it. So if I can just somehow get myself to do it, it often ends up being ok (not always, but sometimes at least!).

I really hope you're able to go to the concert and have some fun!