I win dizzy DAILY?

I get markedly dizzy everyday. Usually when I stand up, but I can just be walking around and I return with dizzy. My eyes go black similar to I can't see anthing but black. I am 20 years old. It is not from not consumption, it happens even right after I do munch through. I have NO IDEA what is going on. Please abet if you can! Do you have big blood pressure? I get headache & dizziness if my blood pressure is high.
sexually live?