night shift??

So I've been doing night shift for the 2 months. I've noticed the last 2 weeks I keep getting dizzy spells and when they occur I get a bad headache and nauseous. I actually checked myself into the ER at the end of my shift yesterday because the dizziness wouldn't go away. They could not fine anything wrong. In looking at my labs my blood sugar level was only 80. I know that's considered normal, but I find it odd because I had just eaten about an hr before that level was checked. I am now wondering if I am becoming hypoglycemic towards the end of my shift. I did have a miscarriage on May 16 at 12 weeks. During that time if I didn't eat something every 2 hours I was feeling weak and nauseous. I know I'm not pregnant as they checked that in my labs yesterday. Anyone else have this issue?? I plan on following up with my doctor but I'm wondering if night shift is screwing with my body.

Thanks :)