Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concerns..
As per your complain
dizziness on bending down along with
sinus infection can be due to middle
ear infection or Meniere's disease..
Other common causes that can cause similar symptoms can be Benign Peroxysmal Paroxysmal Vertigo, stress etc..
I would suggest you to consult an Otolaryngologist and get evaluated and a thorough clinical evaluation and investigations like Otoscopy, x ray , MRI scan, blood pressure monitoring,
Posturography etc can help in diagnosis and treatment can be planned accordingly..
You can be advised to take antibiotics, anti inflammatory painkillers,decongestants, anti allergics like
Meclizine, benzodiazpines like Diazepam etc..
Limit salt intake in diet..
Avoid sudden movements of head..
Avoid driving or operating heavy machines..
Take sufficient rest and a nutritious diet..
Hope this information helps..
Thanks and regards.
Dr.Honey Nandwani Arora.