Hi Guys I need help with my galaxy s8?

Hi guys..
I have run to a very big problem
The problem is that I connected a usb with otg with my mobile and started watching a movie..
The mobile Shuted down by crashing after 15 minutes..
When I tried to turn it back on its battery had jumped from 88 to 25 percent...
And when I started using it (the usb was already removed) it crashed again..
I put it on recharge and turned it on it was doin just normal..
Now it doesn't even turn on when not on recharge..
And works while on recharge..
It also sometimes hangs completly then i have to shut it by force by presding power and vol. Down key..

Now does anybody know where the fault has occured..And Is this problem repairable?
Help is appreciated..