Glad that his mouth looks okay now. Also glad you haven't been handling him since the fall, he may still be sore internally.
So he's NEVER fed for you, is that right? What did the breeder feed him? You should first be offering the same exact prey (size & type- rats or mice).
One thing you're doing wrong is offering TOO often. Don't offer more than once a week, please, as that adds stress too, making him LESS likely to eat.
Then, if a snake refuses once a week for a couple times, you might lengthen the time between offerings to every 10-14 days. I realize that's a long time for a hatchling though & not ideal-
The thing is- we aren't seeing the snake- & we cannot fully diagnose issues online- only try to help you with husbandry issues. Have you double checked ALL his "husbandry"? (what are the hi & low temps in his home? Hides? Humidity? Location of enclosure relative to other home activities- ie. is he in a quiet, unbothered location?)
Are you only offering while he's in his regular enclosure? I hope so- as moving a snake to a side container often results in non-feeding. Be more specific as to HOW you offer him food- tongs? drop feed? time of day? room lighting? It may be time to either try a small live feeder of the right type rodent, OR a vet check (& maybe x-ray for internal problems- broken bones?).
If you need to find a qualified herp vet, this may help:
https://arav.site-ym.com/search/custom.asp?id=3661
Good luck, & please keep us updated.
QUICK AFTERTHOUGHT: I just double-checked how long it's been since you got this snake. We often advise not to offer food for at least a week or two from the date of their arrival, due to the stress of shipping/new home, AND to avoid meal refusals. The handling & fall surely made this worse (harder for him to settle in) but it hasn't been an outrageous amount of time since he last ate for the breeder- that was around the 10th from what I can tell in your first post???
But DO make sure you find out WHAT the breeder was feeding him! Mice or rat, what age/size, live or fresh-killed or f/t? And by tongs or drop-fed if dead prey? Best results come from doing what the snake has learned to expect from prey.