I read your message. This type of problem mostly occures due to impacted wax in ear, which causes blockage of ear after entry of water.
Next Steps
Put wax softening ear drops ( like Otorex ear drops, 3 drops - 3 times in a day) for 5 days. Then visit any near by ENT specialist for wax cleaning. it will be ok.
Health Tips
Never try to remove wax by your self.