I agree that a trip to your good, trusted vet would be the first step.
The only thing I can think of that hasn’t been really hammered is getting the scent out of the carpet or removing the carpet and really soaking the floor underneath with enzymes to totally kill the odor. But that would be after Norman stops marking there.
You might try sopping up his urine and putting the soaked paper towel and Norman in the box. That worked instantly for me with kittens a few times, but not sure about an adult.
Good luck with this, Huntress. I hope that Norman is all right.