Go buy a contact cleaner from Mr DIY. 9-10 bucks.

Open the mouse and spray the contact cleaner on the switches and wait 5 minutes before assembling it back.

It successful, it will work like normal. If the switches already work out, u can try to desolder the old switches and order some new ones and solder it back.

Nowadays even branded mouse all using low quality switches so 2 years is about just right for replacement.

I have tried to upgrade the switches for my Logitech gaming mouse once. Not difficult just need patience. Good quality switches can be purchased online for 3-4 bucks a piece.