April 2024 - Apple Watch SE - New battery drain issue & will not update to 10.4. Stuck on "preparing".

Help! Yesterday my Apple Watch SE battery started draining from 100% to dead in two hours. Before yesterday, no issues with this watch or battery whatsoever. Thought maybe I needed an update to fix the bug, but I cannot download the new 10.4 update either. Stuck on "preparing". Anyone know why I am having this battery issue and why I cannot install the update?

Things I've tried:

1. Deleted the download and tried to reinstall multiple times.
2. Force restarted both the watch and iPhone.
3. Unpaired and repaired watch to phone.
4. Kept watch on charger overnight to see if it needed time, nothing.