it is really slowing/freezing my game. I thought my computer could handle it, but apparently not.

MSGO comes with an uninstaller. So it can uninstall itself whenever you want.

But did you follow the advice in the installer?
It explains that certain computers cannot handle certain elements of MSGO.
It's pretty clear on which mods may not work for your system, so just follow the advice of the MSGO installer.

If the options you picked are slowing you down, then go through the MSGO Options again and select ones that are less demanding.
Pay attention to the diffenret version of MGE to pick, as well as the grass and trees. The more you pick, the more it demands from your system. (grass is especially demanding)

Not only grass - turn off per-pixel lighting shader if you`ve installed MGE XE (under distant land tab) - in my case it had the biggest FPS impact.