Huge Fps Drop

I downloaded prince of Persia sands of time for nostalgia and was getting a Max of 75 fps (my specs aren't good). Now after using a reshade preset, I am getting a Max of 25 that too in the main menu and after decreasing the resolution to 800×600 I am getting above 30 but still not that good and I want to improve the visuals not worsen them. I was thinking to use resahde in other games too but after this fps drop I might not. I have in-game settings all set to max
It's my first time with reshade.
Any solution for preventing this huge drop?

Disable all effects and enable only those that are less hardware intensive? For instance, DOF and AO need good specs to run reasonably well.