I feel for you. I had a sunburn that severe once. Blistered and peeled 3 times.
Only thing that gave me much relief from the constant burning was the sunburn spray with Bensocain in it. Called
Solarcain and available at your Walmart or pharmacy. They have some other similar products. I would go ahead and get the least expensive with the same amount of the active ingredient Benzocaine. It stings when you apply it simply because of the spray and anything touching that burned skin is painful.
I have heard good about
Mederma I don't really know how much it helps.
I had red scar looking skin for the rest of the summer and some of that winter but it eventually healed and left freckles all over. I think my mom prevented some scarring but putting cool wet towels over my back when I first started to blister. I kept it from causing as much damage I believe. Now you are past all that though.
You will need to be extra careful to watch for moles on that area of skin in the future. My sunburn that peeled 3 times like that was back in 1993 or 94. Since then I've had 2 moles removed. One was benign but the other was Stage 2 or 3 cancerous - It just hadn'e grown "roots" yet or branched out enough. No more have been found since so I'm lucky. I still need to watch for them though.
Good Luck.