Good afternoon IrishGrandma62,
Welcome to the Apple Support Communities!
I understand you are no longer using an Apple Watch that your iPhone X was previously paired with. The resources below will help you remove the Apple Watch and check battery usage on your iPhone.
"To unpair a Bluetooth accessory, tap Settings > Bluetooth, find the device you want to unpair, and tap , then Forget this Device.
When you Forget this Device on your iPhone, iPad, or iPod touch, that accessory is removed from the list of available Bluetooth devices."
Source: Pair a third-party Bluetooth accessory with your iPhone, iPad, or iPod touch
Find My iPhone: Remove your device
About the battery usage on your iPhone, iPad, and iPod touch
Take care.