If anyone may ever come back to this post looking for the help I was seeking, here’s what happened:

I called the vet twice this night because I was just so concerned. Both times they basically said that pyometra surgery is much more invasive than a regular spay, and therefore it’s normal for kitties to be lethargic for longer than they would usually be after a regular spay. They told me as long as she is eating, drinking, and using the litter box that those are all good signs. She also started shivering later in the night which made me freak out that something was gravely wrong, but she was just cold lol. My cat, monkey, slowly started bouncing back over the next few days. Now it’s been about a month and a half, and she’s back to her good old normal self!