Cup feed would be a good way of slowly rehabilitate the tongue, you can increase the distance to shoot incrementally. Perhaps try a few different cups/vessels,
I just hold calciworms and medium silkworms in my palm now to do a range check (its actually quite something as i used to have massive phobia of maggots

) i also have a cup low in cage for worms and a run cup up top for staples.
SeriouslyFinding a good knowledgeable vet in the situation you faced was the best thing to do & happy to hear it isnt a illness rather a one of those one off freak accidents hope you're chameleon makes a full recovery