Apple Watch Series 4 - waterproof

My apple watch stopped working. Do not see anything displayed. I think it still connects to the phone. The side button of the watch is not working. I swim everyday in the flat part of the ocean * salt water * for about 1/2 hour. I am not sure if the water troubled the side button which had jammed and later one end raised and opened up a little bit. I am located in Jamaica and without access to any professional assistance. Please can someone advise me what to do? Thanks