Not much I can add...I would definitely get a second opinion somewhere if I were not satisfied. I will say that I had a foster pup once who had a heck of a time because of his tongue after extractions... there was nothing wrong. He just had a difficult adjustment.
The one thing that I can suggest is that, if you end up using Gabapentin long term, you can get it in tablet form. The liquid is nasty and I gave up trying to give it because it caused my Pippi so much distress. She was taking it for IVDD and would shake her head, scaring me that she was irritating her neck more. I got the tiny tabs from Wedgewood Pharmacy. Problem solved!
https://www.wedgewoodpharmacy.com/