I sympathize with the anxiety. I have anxiety, too. But one thing to keep in mind is that failing is fine. Dying is fine, wiping is fine. There is barely any punishment for it besides having to start the fight over. I'm also a slow learner. Some mechanics take me ages to comprehend. Sometimes I have to ask either my friends or the party for clarification. That and I'm sure there are video guides out there. I know I watched them all the way up till Endwalker because I was so scared I would drag the party down by being bad. But then I finally realised that there's nothing to be afraid of.

Mistakes and failures are a natural part of learning. For everyone. Some people get things faster and make fewer mistakes, some people need more time and help. But giving up won't help you progress.