hello and welcome to HCM,
It is unfortunate that even when you are having muffled hearing you are consulting the pharmacist.
Although your problem may not be severe in all probability, it is always better to consult an ENT rather than take a chance.
There may be several causes for your problem and these have to be ruled out
The urgency is because if you are suffering from a condition called the sudden sensorineural hearing loss
then the treatment given in the first 48 hours determines the prognosis. So please do not wait anymore and get yourself examined by an ENT
It may finally turn out to be just a cold
or block which can be relived by an antihistamine and steam inhalation but better to be safe than worry
Dr Sriram Nathan