Usually a reset will clean up any looping code that can cause excess processor usage (and battery drain) - but it seems you have already done that.
Something in the last update is causing issues with custom watch faces - I haven't seen people talking about battery drain, but it may be worth reverting to a standard Garmin watch face and seeing if that resolves the issue.
It's probably time to contact Garmin Support (including details of what steps you have taken so far).