Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concerns..
As per your complain it seems that blackish discolouration on the tongue of 5 month old is most commonly due to poor oral hygiene
maintenance that leads to abundant deposits of food debris and also bacteria and fungal overgrowth over the tongue leading to formation of a dark coating over the tongue..
It is a condition called Black Hairy Tongue
It is however harmless and can be gradually removed if proper oral hygiene and cleaning of tongue is done..
You should start cleaning her tongue using a soft toothbrush..
Give her solid foods to eat..
Use a tongue scraper to gently clean her tongue..
Feed with plenty of water..
If she tugs and pulls her ear again and again then there must be probably infection still present in ear and for this consult a Paediatrician and get evaluated and get a proper ear examination done so that she can be advised antibiotics oral as well as ear drops along with pain relievers..
Hope this information helps..
Thanks and regards.
Dr.Honey Nandwani Arora.