Green/red snake of dead on my Apple Watch

I have my Apple Watch as my birthday present on December 15th, it have 84% of battery capacity. On February 15th, I gone swimming with my Apple Watch on my wrist, it at 85% charged. After I go to swim, I left it on the charger and I have dinner, a while later, my iPhone says that it was 100% fully charged, but I didn’t care. After I have dinner, I got to my Apple Watch and it didn’t turns on. I left it cools down, and charged it again, but it shows green snake again and again, then it shows red snake of death. I left it off the charger. Then, at night, I put it on the charger and it shows overheat symbol, despite it wasn’t hot. Can anyone help me that?!?! From that date on, I charged my  Watch and it only show green/red snake of death