Apple Watch pairing

I can't answer that question. We are all users on this user to user only forum. If you would like to get help from Apple, schedule an appointment at your Apple Store Genius Bar and let Apple run diagnostics on the watch.

Why does your watch die? The battery was depleted or some other circumstance. I've personally never had my watch die, nor ever have to pair it again. We need to dig a bit deeper into the circumstances under which your watch is dying.

It's really not healthy for the battery to become drained completely. I'd make sure to charge it more frequently, especially if you plan to sleep with it on your wrist. Unless you are using sleep tracking, the absolute best way to ensure a full charge for the next day is to put it on its charger when you go to bed, with Optimized Battery Charging turned on.