Apple watch series 6 not charging

Hello everyone, I'm reaching out because I have no idea what the problem with my Apple Watch Series 6 is.

I’m on vacation and over the past few days, I’ve occasionally worn my Apple Watch in the water, both in the sea and the pool.

Then I kept wearing my Apple Watch until the battery dropped to 0%, and the watch turned off.

When I tried to recharge the Apple Watch the next morning, I noticed that it no longer works.

When I try to charge the watch, the Apple logo briefly appears, but after a few seconds, it disappears again. Instead of charging, the watch only heats up, and the logo reappears a few times. It seems like the watch repeatedly tries to restart, but it doesn't work.

Does anyone have any idea what the problem could be and what I can do? Could it be water damage?

TL;DR:

My Apple Watch Series 6, after being worn in the sea and pool and draining to 0% battery, won't charge. The watch briefly shows the Apple logo but then turns off again while heating up. I suspect water damage and am asking for advice.