I've been getting dizzy spells recently too...I don't usually get them and like you, they can last for a few hours.

I've actually put mine down to lack of sleep...not sure it that's right or not...but when I sneak in another hour of sleep, I do feel better.

I've been breastfeeding for nearly 8 months now and they have only started in the last 2 weeks...so I don't think it has anything to do with breastfeeding...

Good luck with breastfeeding...it really is lovely, hey?