Watch will no longer pair with app, no matter what I do!

I noticed that my Lily watch, which I've had for over a year, was not connecting consistently to my iPhone via the Garmin Connect app. So I deleted the app and re-installed, and it didn't work. So I "reset" the watch, and now it won't recognize it. I've tried toggling Bluetooth on and off, restarting my phone, charging the watch... nothing works. Getting very frustrated and tempted to go out and buy an Apple watch instead...