I haven’t read all the advise so I’m not sure if anyone has said this yet. I know there’s been a bit of hinting at knowing your routine inside and out, but you should really KNOW it inside and out. Script everything, in detail. Every step you take, ever facial expression you make, and of course every trick you do and at what speed and in what way. Write it all down, and then time the writing with the same parts of the song every time. Start with timing it all with the song and then write it down after, or as you go along. Then practice the written routine as much as you can every day. I’d advise an hour of repeating it every day, but more would be even better. If you don’t have this much time to put into your routine I understand, but it will help with the anxiety as you will know inside and out what you’re to do next. Which help loads with the confidence.