Why do people have headaches with AM Bp?

First of all I have never smoked. The doctor told me that because I have a very low heart beat to begin with 55-60, sometimes in the 40's, when I am up and around in the am that the BP medicine has a tendency to lower it more when I am laying down. He told me that and took me off the medication. After being off the medication all that gasping for air stopped!!!!So it must have had something to do with it. But, the headaches still continued and he said to search for something natural that would help to stop the headaches in the am. So that is what I did and now the headaches left when I started taking BComplex and Vit E or any other oil Vit E, A or Omega 3's. Taken right when I go to bed. I believe I have an adrenal problem as my heartbeat stays too low if I don't take something to drive it higher like up to 80 which is normal for a worman. When I drive my heartbeat higher my blood pressure goes down!!!! My BP was instantly caused when I had a hysterectomy. It went from low bloodpressure of 110/60 to 154/90 over night. My girlfriend who owns a health food store and is a nutritionist says my BP was caused by a hormone imbalance!!