I feel your concern. this same thing happened to Oscar it was also on the wrinkle of his face and did not improve, eventually I took him to the vet for surgery, I too cried, it's natural. I felt awful because he was so happy to go on a car ride and I left him behind like a bad mommy. Don't worry, I'm sure everything will be ok. You probably won't even notice a scar when the hair grows back. I hope everything goes well. Oscar and I will have keep you in our thoughts and prayers.
Paula & Oscar