I have a migraine, a non stop bloody nose (only when I blow it) and I've been having dizzy/fainting spells. What could this be?

Migraine. Several things could be going on you should go be checked by a doctor.
As above. Nose bleed can be related to many reasons , i agree with other physicians to see u p p for evaluation and work up.
Could all be. Migraine related but further evaluation with your physician is warranted.