Once when I was camping I decided to try to use a plastic bottle as a pillow. I put my head on it sideways and the plastic made a really loud pop and my ear instantly started ringing really loudly like nothing I've experienced before. I was deaf in that ear for about a minute while it rang and it terrified me. Luckily it went away.
More recently something happened to that ear. It started to get water in it every day then stopped getting water in it but now I have tinnitus in that ear.
Ears are extremely sensitive and it doesn't take much to damage them.
You may have a sticky wax or otherwise blocked ear that was trapping the water. Wax or other buildup in the ear can cause tinnitus (and of course attenuated hearing, ranging from imperceptible to completely muffled).
It would be worth going to see a doctor and get them to check inside your ears.
You certainly wouldn't want to spend weeks thinking you had permanent tinnitus or hearing loss when it could be as simple as an ear flush. I can tell you that from experience.
More recently something happened to that ear. It started to get water in it every day then stopped getting water in it but now I have tinnitus in that ear.
Ears are extremely sensitive and it doesn't take much to damage them.