Unable to pair my iPhone 12 mini with Apple Watch 7

I deleted the watch data on my 12 Mini and reset the watch because I was going to sell it. However, I decided to keep it but now it won’t pair with my iPhone. Every time I try it wants to run a watchIOS 11.1 update on my phone app before doing anything. The update keeps switching from 2 to 3 to 1 hour. I’ve even had 9 minutes come up, but it soon switched back to 1 hour. After unpairing and restarting the watch (even a forced start), i can’t get past the software update. When it did eventually download ready to install on the watch (via the phone), I got a message the watch was not over 50% battery, but it’s been on its charger for over 2 hours. I’ve been trying to get past the update since last night. Since early this morning it’s now stuck on 1hr (having reached 48mins, 10 mins ago).

[Re-Titled by Moderator]