How can I fix pressure spots on my monitor?

I've just suddenly noticed a dark spot on my screen (not black, just a bit darker, like a shadow) and it's really distracting, as it's quite close to the middle of the screen. I've done some surface level research and it seems to be a pressure spot. There's also a bit of a distortion on the back of the monitor (just a few inches to the left of the dell logo, from the user perspective).

Does anyone know a way I could fix/improve the issue without having to pay for costly repairs?