Anytime I take a spool off the printer I put it back in the filament dryer. Once it's done it goes in a sealed bag with dessicant. This keeps the filament dry and prevents stringing.
After the Ender 3 Pro, I got a Bambu X1 Carbon. I have been running it for over a year now and it just makes whatever I send to it. The few times it has needed my attention, the instructions were clear and easy to follow.
With mice, the screws are always hidden by the glide pads on the bottom. It looks like an ASUS WT200 but after a quick look I can't find any for sale.
Ok if you can't get replacement guts, it might be something easy you can fix. Maybe some paint got on the laser or the lens. Flip it over and have a close look at the little hole. Some isopropyl and a q-tip might get it working again.
Don't feel bad, you come from a long line of men who got it done before buyer's remorse set in.