Cooling the skin will help stop the skin from continuing to burn....try putting cool, wet cloths on the area (having a cool shower or bath seems more effective but then you have to towel off at some point which sucks with a burn). Put lots of aloe on the area and reapply often (this should reduce the damage to the skin and start to repair it). Also, you should limit your sun exposure for a while but staying out of the direct sun and wearing long sleeves. Be sure to wear lots of sunscreen in the future...they say it only takes one bad burn to greatly increase your risk of skin cancer :(
U can buy aloe gel and chill it in the fridge and continuously apply! I'm from the sunshine st and had my fair share of burns. This helps! Or try solar cane as suggested to me once by a dr. U can buy either at any drug store or walmart!
Aloe is good. Banana boat lotion is good and seems to help you tan. If youre in extreme pain, get a wash cloth and put vinegar on it and just leave it on the burned area. You smell a bit like a dinner salad but ohhhhhhh instant relief.