We are taking the jacket off a couple times a week to let the skin air out and so that she can clean herself naturally, but this one spot is horrendous. There is some hydrocortisone on the area, and she was licking herself as I was snappjng these.
Take your cat to the vet. If you insist on using the internet as medical advice for your pet, find a more appropriate place than this. Then also consider surrendering your cat to a friend or family member that can take them to the vet. Best of luck.