Help increasing my blood pressure.

• female, 27, Caucasian, 145lbs, 5' 10"
• I take topamax and prozac daily
• Migraines several times a month
• Tension headaches almost daily
• Last few BP readings are 76/54, 85/56, 104/67, 84/55, 86/59, and 94/53. All of them were taken around 6pm during the past two weeks.

Over the past five years I've had a difficult time standing up from a sitting or laying position. Even if I stand up slowly, my vision goes black and I have to hold on to something to keep from falling over. While this is happening, my arms and legs feel like jello and I can feel my heart pounding. It normally takes about 10 seconds before my vision comes back and I can stand on my own. My doctor had advised me to salt my food and drink water mixed with Gatorade, which I have been doing for the past two years. These have helped a little but I'm still having the same problems.

Does anyone have suggestions on how I can fix this? Or at least know how to increase my BP enough so I can see when I stand up?

Thank you!