It will take a long time to heal properly maybe a few weeks. You must not go on beach in hot weather without sunscreen at a high factor then keep re-applying it. You could have been taken to hospital with severe burns to your skin. It sounds very painful so go to the chemist/drug store and get some cream. A lot of people learn the hard way about this even after all the advertising etc there is. You can get skin cancer from to much sunlight. Good luck I know how it feels and you have my sympathy.