Needs detail physical assessment.

Hello sir. Unsteadiness and lightheadedness are caused usually by disturbance in vestibular i.e. balance system inside the body. It is divided into peripheral i.e. due to problem in the balancing organ inside the ear or central i.e. peripheral. A detailed evaluation and discussion with you will be required for proper diagnosis and treatment.

BP and physical examination needed.

Maybe sinusitis. If you have constant headache then you need proper treatment