Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concerns..
As per your complain it seems that due to injury of the ear canal
with the metal tube of the stethoscope that led to sharp pain
and now having moderate pain seems to be most probably due to injury inside the ear canal leading to injury to the lining of the ear canal and due to inflammation caused by injury there is pain..
Another reason can be perforation of the eardrum caused due to deeper penetration of the metal tubing leading to pain and discomfort..
I would suggest you to consult an ENT Expert and get evaluated and a thorough clinical evaluation and investigations like Otoscopy can help in diagnosis and treated accordingly..
In case if there is only injury to the lining of ear canal then antibiotic and analgesic
eardrops will heal it.
In case if there is perforation of eardrum then small perforations can be healed with oral antibiotics
and anti-inflammatory painkillers like Ibuprofen
and antibiotic and analgesic eardrops.
In case of large perforations surgical repair might be needed..
Hope this information helps..
Thanks and regards.
Dr.Honey Nandwani Arora.