It may be a reaction to the mediation you took. I was on an antibiotic that burned my tongue and tongues heal very fast--but this took 3 weeks! For relief I rinsed my mouth with organic coconut oil (may or may not be wise-I have no idea) but it took the pain away for a bit.
THAT HAPPEN TO ME WHEN I HAD STREP THROAT BUT IT WAS THE ABX I WAS TAKING SO YOU MAY OF JUST HAD REACTION TO UR MEDS
If you were taking antibiotics, this could be a reaction from them. Most antibiotics not only kill the bugs that were causing your bronchitis, but, they will also kill all the friendly bacteria in your system as well, this will cause the sore and red tongue.
I suggest you take a good, pro-biotic to put back the friendly bacteria, this should help to clear up the problem.