I’ll share what I learned from my wrists and forearms getting pretty bad 5-6 years ago.
In no particular order:
1. Tendons strengthen very slowly. You can build muscle strength over the course of weeks or months but for the delicate tendons in your wrists you’re looking at years. That means you have to take it easy for a very long time to build up strength in that part of your body before it can take heavier strain
2. I highly doubt it’s specific to your mouse and more likely has everything to do with your set up. You need to find a relaxed position that takes zero effort to exist in. For me a lot of that comes down to desk/chair height as well as pads to hold my elbow and wrist in the exact ways that are comfortable for me
3. There is a holy trinity of preventative and curing techniques for your wrist pain: stretching, sleep, and warmth/blood circulation. These 3 things are the most effective thing you can do to heal and prevent further damage ONCE you’ve addressed your set up.
A: stretching is the ultimate way to relieve pain and set yourself up to heal: You’ll need to find stretches that affect the hurt areas (experiment and look up examples). My most effective stretches were not things I found directly online, but they were inspired by stretches I found online. The most effective times to stretch are during and right before sleep. Do NOT over stretch, you’ll delay healing
B: Sleep is the ultimate way to heal. I find it works best as a 1-2 punch with stretching directly before sleep, and then keeping your wrists in a relaxed neutral position while you sleep.
C: warmth/blood circulation: wrapping or compressing your wrists to keep them warm and well circulated both while using and when sleeping is the ultimate way to prevent further damage and bolster healing you get from sleep.
This is of course my personal experience, I’m no physical trainer and haven’t spent extensive time researching this stuff. But it has worked wonders for me and I have next to no wrist pain today despite using computers most of the day at work, and gaming most evenings/weekends