I grew up at the pool. I was a lifequard until my 20's. I lived in MD and I usually had one mild burn every year. Now, I live in SW Florida and I never go out in the sun with less then 30 SPF, a had, and sunglasses. I burned my left arm and shoulder down here on a road trip to Daytona beach way back in '82. I spent 3 days on the beach with my left arm and shoulder under a towel it was burnt so bad.
So sorry for your misfortune!