Re: Ukemi and Dizziness
HOLDING YOUR BREATH - that might work for some, but I won't recommend it. Its likely to create tension in your body and result in injury. Instead try exhaling softly (not deliberately, but naturally).
As a note, you can do solo ukemi holding your breath I suppose. Its the danger that you do the same when someone throws you and you're no longer in control that's the problem. Relaxing is foremost.
How holding your breath will help you in terms of dizziness, I wouldn't know.