Dissolve 1 pound of baking soda into a tub full of cool water and soak for about 30 minutes - that should relieve some of the pain and stinging, then use lots of aloe gel (I keep mine in the fridge so it's nice and cool) and a mild moisturizing lotion (meaning use stuff with aloe or vitamin E rather than anything with scents or non-sunburn/skin repair-related functions) and take some ibuprofen. Be sure to drink lots of fluids because sunburn dehydrates you. I hope this helps!

thanks for the lovely comment! that was sweet!

seriously, if nothing works, just get some tylenol pm and sleep! your body shuts down all but emergency pain receptors while you're sleeping... take a break!