Suddenly burning through battery faster than watch can charge. Digital crown scroll not registering.

Series 4 (GPS Only Model) has worked great for a year and 1/2. Few days ago, my watch unexpectedly starts draining battery. From 100% to 65% in an hour. It drains faster than it can charge, and loses battery (less slowly) even when on the charger. Have tried multiple chargers, cables, etc. Only way I can get it to charge is to put the watch into Power Reserve. When finished charging the device is warmer than usual, but not hot to the touch.

Digital crown no longer registers when scrolling. The press function still works.

As far as I know, no drops or unusual usage led to this. I do, however, take my watch surfing 4 days a week - and have ever since getting it a year and a half ago.

Have tried restarting, and also a hard resets. Have not tried un-pairing, or factory reset. Ideas? Thank you to any an all responses.