SB2 Base Fan Doesn't Work. Anyway I can fix it?

I am like 80% sure the fan is the issue. Normally when playing video games, I can hear my fan blowing and its pretty loud, but I can just barely hear it these days.

When I load up a game, I get my usual 60fps but it slowly starts to decrease and eventually stabilizes around the 10-15 fps mark. My assumption is that the GPU is thermal throttling due to a lack of cooling being provided by the fan.

Honestly I just want to check what my fan speed is but there doesn't seem to be a way to do as I don't think Microsoft lets any software access that particular data. Is there a way I can fix it myself without taking it to a repair shop?

If someone thinks the issue might be because of the GPU, please let me know.