It's difficult to tell from the image, but I think I spy leaf miner trails and blotches. Maybe if you removed a leaf or two to take a picture, I could see the problem a little better.

It's certainly not mint rust. At least I AM sure of that. :-)

I agree - not mint rust. Maybe spider mites since you see webs? To see if it's mites, hold a white paper under the leaves and shake the plant. You will see the tiny little mites on the paper.

Drought? water shortage?

"Webs around leaves" could be leaf rollers or leaftiers.