That does sound a lot like vertigo. Especially the part about turning your head and getting dizzy when you lean your head backward. Have you gone to see an ENT yet? They could provide you with more answers than a regular doctor. The meds they give for vertigo would be like meclizine. Or Valium. Meclizine works well but it knocked me out when I used to take it for vertigo. Valium is better, in my opinion. But unfortunately it's highly addictive.