Updating an Unpaired Apple Watch?

Hello,

I have an Apple Watch series 1. I hadn’t used it for about of month and the watch eventually unpaired, and fell behind on updates. Now when I try to pair it again i get an “update is required to continue pairing” prompt. However, when i try to update the watch, it never goes through. The app says the watch update has been downloaded, then i click install and it goes through that process. But when it finishes it goes back to the original “download and install” screen and the watch still hasn’t updated. Is this watch a lost cause or has anyone else been able to troubleshoot this problem?