This sounds like Swimmer?s Ear (otitis externa), where trapped water causes inflammation or infection in the ear canal. You should see a doctor to ensure your eardrum is intact before using any drops. If it is safe, a doctor will likely prescribe antibiotic and steroid ear drops (such as Ciprodex) to quickly reduce the swelling and pain. For immediate prevention, keep your ears completely dry during baths using silicone earplugs or a cotton ball coated with petroleum jelly. Avoid inserting cotton swabs, as they push moisture and bacteria deeper. Over-the-counter pain relievers like ibuprofen can help ease the pain temporarily.