I hope you are feeling better.
Do not worry every thing will be fine.
According to your history this is probably vitamin B12
defieciency,titis media along with some throat infection
which can be tonsillitis
.Now as for the muffled hearing and ringing in ear,it is because our throat and ears are connected from inside so if there are more fluids in your mouth which are increased due to tongue sores the fluids goes in ears from inside so you feel ringing and hearing decreases.And due to vitamin defieciency sores appear.
Now this a curable condition and with just proper medication you will just feel fine.
So here whats you need to do:
1.Visit your ENT Specialist
who will do a complete examination of your throat,ears and use an instrument to see inside of your throat.
2.He will prescribe antibiotics and vitamin supplements
3.In the mean while before you go for a visit do following:
(i)Take plenty of fluids like tea,coffee,soups etc every 2 hours
(ii)Inhale steam before going to bed
(iii)Eat citrus fruits,lemon,chicken,egg daily
(iv)Keep your self warm.Don't go out in cold
and relax your body you will feel better.
Good luck and get well soon