Teeth Chronic molar problems now

Who's There is 6 years old and has molar problems. Almost 4 months ago he had them filed down. He is showing the same problems and has had his fronts trimmed already. Even with pain meds I can tell he still has pain, he stays hunched in his tent all the time. I feel so bad that he's in pain so I set up a appointment to have him PTS on Friday. He will only eat his critical care/mush mixture, a few shredded carrot pieces and maybe a bite of banana. So he is losing interest in food now too. He's never had free range so last night knowing this was coming, I locked up the cats and let him roam, he acted like a young pig again and I thought maybe it was too soon to think about him being put down. Today he was back to hunching over again. I am thinking a few more days of free roaming for him to let him forget his pain for a bit. Just trying to give him a good send off, am I wrong to think this way?