Welcome in H.C.M.
I read your query and also analyse your doctor's advice, as per specification of your dizziness
for a moment, it appears to be vertigo
or a variant of minier's disease.
As your MRI
of brain is OK it means no central lesion is suspected. You are advice to go for good neurological examination by neurologist
and investigations for vertigo like ENG etc.
You have not mention about your hearing and ringing sound in any ear as these are important for making diagnosis.