My apple watch series 4 will note download latest iOS - it keeps saying my phone is unpairing watch

So I lost my Apple Watch (Series 4 - 40mm) for about 6 months and when I finally found it I charged and tried to connect but it said I need to pair it again with my phone (iPhone X) so I did the following:

1. attempted to pair my iPhone X with my series 4 watch.
2. My watch goes to a screen that shows the apple logo with a bunch of spirograph lines
3. My phone app for the watch says "Update your Apple Watch" - so i clicked on update now since I have to pair with the latest watchOS - so I click on "Update Now"
4. Message pops up - Unpairing Apple Watch - it does this now every time.

This is where I am stuck as I keep on going back to step 1.

Please help.