How can I fix my desk?

Alright, so before buying a fancy gaming mouse, I was stuck with a standard one, which didn’t track well on my desk surface for some reason. I used a piece of paper as a mousepad. Now, this is a small room, I am running a PC with Four hard drives, 3 monitors, two video cards, and a partridge in a pear tree, and without a fan it gets up to 30 degrees Celsius. Since it was so warm my wrist got sweaty from staying in the same spot, and for some reason that has messed up my desk surface, here’s a picture.

Now because the surface is like that, my new mouse doesn’t track well, and has trouble reading the surface sometimes. I was wondering how I could fix it. I’ve been contemplating getting some latex or maybe better would be water paints, painting over then lightly wiping off the surface so that it just stays in the scratches in other parts of my desk, but that area doesn’t seem to have many dips down, it feels a bit rougher but not much.

How can I fix this for cheap?