Hello,
For sunburns, use a sunburn Over-The-Counter remedy containing aloe vera and a light moisturizer or a dusting powder to relieve chafing. You can apply silver sulfadiazine (1% cream) on the skin except face and see if it helps.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
There isn't much a doctor will do. The ointment they used to prescribe is not used much anymore, as it causes the skin to turn black.
Make sure to cover the blisters as they pop to avoid risk of infection.
Flour...yes flour, can be your best friend. Try covering the worst areas with it. It will soothe the burn quite nicely.
Sunburn in any form and stage is quite painful. Stay in the shade, apply ice if it helps, apply aloe or any other lotion ( calamine ) that doesn't make the sting worse.