Low Blood Pressure

The doctor has declared that my blood pressure is constantly below the average. That normally doesn't bother me too much though I used to have a few fainting spells every year. The doctor can't really figure out the causes for the fainting but assumes that it "might" relate to low blood pressure. However, things are getting worse lately because of my irregular biologic clock I guess. The whole world around me looks very funny as I can see two or more exactly the same things appearing in front of me. Sometimes the world itself is spinning or I'm the one who is spinning. Anyway, I thought I have been used to it but now it proved to wrong because I really hate the dizzy feeling.