Any reason why you needed to reinstall Windows every couple months? Though that would only account for a relatively small portion of the write activity.
SSDs have a limited number of writes that can be performed to each cell, and that's what the health rating is indicating, the number of remaining writes that the manufacturer says the drive should be able to handle. At your current rate of writing over 100GB of data to the drive every day on average, you have been using around 1% of the available writes per month. That's a high amount, but even if you continued at that rate, it might still take over 7 years to burn through all of the available writes, by which point you may have switched to using a different SSD as you primary drive. If you did hit 0% though, depending on the drive it might either lock it into a read-only mode, or allow it to continue working until the drive fails, which could potentially be a long time afterward, as manufacturers often underestimate their official endurance ratings.
Since you mentioned primarily using the system for gaming, might you have some video-recording feature active, that could be writing a video file to the drive in the background while gaming? I believe Nvidia ShadowPlay, for example, offers an "Instant Replay" feature that can be set to constantly record a rolling buffer of video footage to the drive, allowing one to save footage of recent gameplay after it happens. Something like that could eat through SSD endurance.