I can relate to how you feel. I hate it when anxiety stops you doing things you need or want to do!

I would suggest you look into mindfulness, that is being in the moment. Its a good way to relax and stop your brain from whizzing and thinking up worst case scenarios!

I think you probably have a lot of self confidence issues, I know I do. Practise self compassion and look how you are speaking to yourself.

You could try the book 'Feel the Fear and do it Anyway', I am gonna give it a go ...started reading it a while ago but didn't get into it but I think it might just have something to offer me now.