I have a mini potbelly, it has very light/thin hair and we left it outside today. It got a bad sunburn and its skin is a dark pink tone right now. Is there anything I can put on my pig to help it?

How sad!
Why didn't your pig have shade provided for it to get to?

Sorry but leaving your pigger out in the sun with no shade is really irresponsible. Pigs can die form heatstroke and buning of the skin can cause skin cancer. I would recomend going to your vet as by your description it sounds quite severe and your pigger must be in pain. Please Please Please do not leave your pigger out in the sun again
Good Luck