i think u need to make good nutrition pattren i mean u should to take complete diet and drink alot of fluides and juice .usually haypotention due to bad nutrition .and when u feel that u hypotention eat some thing salty that is help to make ur blood pressure increase .and care about the fresh vegtables and fruties . do u make blood test to see how is ur hemoglobin? may be u have anemic or some thing. and what is the dr told u about ur hypotenion and what is the causes of it?

I did have the same problem as well. U may try taking some iron tablet.