I am now running around 1-3 fps after fixing my game crashing and cant fix it.

My game would crash from time to time but i did not mind but shortly after crashing i tried relaunch the game and got a error code saying something like the resolution was unsupported and after fixing the issue my game now runs 1-3 fps I used to get great fps but can no longer play the game do to this. i have done a windows scan, reinstalled, reverted changed files, and verified files and I still can not play this game. i was working great until today. and i have only found 1 person with the same issue and they never got a solution.