Poor, poor Jarv, and poor Helen!
I do hope it goes well tomorrow, that he isn't too distressed tonight or in the morning when you take him to the vets, and that he is soon feeling much better.
Just think how sore even a little ulcer is in your mouth, I often used to see the poor patients with facial injuries after RTAs and think how badly I would cope with any pain and swelling around my mouth.
(((HUGS))) to you both.