It might be a shortage of iron in your system. I had dizziness at around that time. I would get a hot flash feel dizzy and almost faint turns out I had pregnancy enemia and needed to take iron suppliments. You might want to have your doctor check you out to see if you could possibly have that. I sign that you do is eating ice.
Oh I forgot about that. My friend had that...! Yes have them check it out
Is is possible that this could somehow be pregnancy migraine related. I had an onset of migraines in my first pregnancy about that time that did not include pain, but I had extreme vision disturbances. It was terrifying. They ruled it migraine related. Just a thought to check out. Good luck!
I never had this with my pregnancy but it sounds very upsetting. I think you should insist the doctor check EVERYTHING! I hope everything looks good.