Wow! Sick picture of a sick watch. My best guess is that the obvious cracks and damage (which look to me to be substantial) have finally caught up to it and are now affecting the performance of the device, even though they hadn't up until now.
It may well be time -- or, more precisely, it may well be time in about a month a so when the next new Apple Watch model is widely expected to be released -- to trade in the watch for whatever value you can get (the fact that its display doesn't work will of course impact trade in value) and buy a brand new, shiny and beautiful Apple Watch.
You could, of course, seek to get Apple Watch serviced. But, my own view the cost of doing so versus what you get with a new one, is that the service option would not survive a cost-benefit analysis, as accidental damage is not covered under the warranty. The cost calculus changes if you have AppleCare+ coverage, which may well militate towards service and not replacement. But that's still a personal decision and not necessarily a slam dunk one way or the other.
Good luck!
-- JDee