Vivoactive 4s won't turn on

After 3 years, it won't turn on. The last two weeks the battery has become increasingly worse, to the point it wouldn't last more than a few hours. I remember my Vivoactive 4 was exactly the same after 3 years but I was in a strong financial position where I didn't mind buying a new watch. I'm now in a very different position, coupled with the fact I shouldn't have to replace my watch every 3 years, so I'm looking for solutions on resurrecting my watch please.

Anyone else experiencing this or have any resolutions?