Place your phone in a ziploc bag with silicon packets(packets found in beef jerky bags) in it and leave for a few days if you dont have any you can buy a bag on amazon for cheap for a couple hundred. If after a few days still doesnt work take the phone apart and check for any rust or deposits. If you are not technically able then take it to a phone repair shop they should be able to clean the phone up and fix it for you. Sometimes it may be a shorted battery that needs replacement so I would check the voltage on your battery also. Good luck