Vinegar stinks, but it takes the sting out of your sun burn. Also shaving lotion is good.
Double up on Viamin C and your liquids and it wouldn't hurt to take some Vitamin E for the skin as well.
You need to get fluids back in to moisturize the skin - possibly keeping you from peeling or blistering.
You will probably be down with your sundburn for a few days at least.