@kainoa I did this by accident on a trip to Portugal in 2016. It's miserable. I was always used to my Sicilian skin getting red then deep tan in a few days. I didn't realize that a white sand beach was far more dangerous than a regular one, the doctor in Portugal said it was closer to a microwave than an oven.
Go to the doctor, get a strong antihistamine to stop the sun allergy part (where you blister at the touch of sunlight), get a skin cancer screening in a few months. Keep cool.