Feel Dizzy when meditating

I don't recommend holding your breath for that long at all, especially if you're new to it. The whole point of deep breathing exercises is to facilitate the movement of oxygen throughout the body, especially to the brain. By holding your breath for that long, you're acutally cutting off your oxygen supply. Was it 5 times in a row? Because that would explain why you felt like blacking out...it would have essentially stopped oxygen from going to your brain. And, your muscles would have built up lactic acid, which would cause stiffness, instead of relaxation. I say, stick with just simple deep-breathing for now. And, if later you feel like you want to try something similar to the holding-your-breath thing, consult someone more experienced, like a specialist...but maybe even just a friend whose been doing it for awhile.