How Can Dizziness And Elevated BP Be Treated?

Hello, I was in a severe headon collision 10 yrs. ago began to have a few vertigo spells, then 1.5 yrs. ago after a severe bout of food poisoning and vomiting it immediately kicked in and started feeling mildly dizzy all day long. A few months ago I began to notice more and more dizziness all day long, and have been checking my BP my high BP is 120/80 my low can be 94/72 it fluctuates greatly and most of time it runs sytolic and diastolic between 22-40 inbetween, I have been through many surgeries due to car accident, hip replacement due to that, and breast cancer almost 3 yrs. ago. I am 50 yrs. old. I am currently in process of going in for MRI soon, and also ABR Auditory Brainstem Response, since I have had surgeries no one has ever mentioned heart issues but now wondering? I have had EEG s or EKGs prior to surgeries with no issues?