Hello, I completely understand your concern for sun burn. It appears from your query that you are suffering from sun burn of quite higher side. In my patients I prefer to give an antihistamine such as levocetrizine for 2-3 times as updosing in a day for immediate relief. Application of mild steroid lotion helps in reducing the burning sensation. If you are not getting better or the problems are increasing in 24 hours then can take a proper medical suggestion from your treating doctor. I also suggest you to do sun protection strictly. I also recommend you rink plenty of liquids so that proper hydration can be maintained. In my patients with your condition I recommend them to use an antihistaminic tablet such as loratadine which is non-sedating one or cetrizine at night time. You can obtain further direction from your treating dermatologist. All the best.