Try wearing baggier clothes and drinking lots of water before you perform – this will keep the body temperature down and will thus help with the redness if you should blush; even a mini-fan or just taking deep breaths before you perform could help as your skin will be a lot cooler so you’ll be less likely to turn pink. I think the key factor is just to relax and calm your nerves; you’ve got nothing to worry or get embarrassed about, so just enjoy yourself. Also, with the sweating problem, try anti-persperant deoderant. This could also help with the blushing as you’ll feel more confident about your problem and will calm down. I know you said not thinking about it doesn’t work, but try not to dwell on it or overthink it. This will help calm you down and will lower the blushing. Blushing and sweating isn’t uncommon in performers; I think you’ll find most musicians go pink/sweat from the effort they’re putting in to their performance.