I had this with my second, you just need to be sure you drink plenty of water and have a couple more snacks a day to keep your blood sugars Up :)
You should probably call your doctor, especially if you're having any confusion, blurred vision or swelling as these can be early signs of preeclampsia.
Here's some advice from the MedHelp website and our I'm Expecting app on dizziness. You can find this in the app by going to the Pregnancy Diary from the home screen and selecting Morning sickness from the Symptoms menu. Then click the menu bar in the upper left and select Symptoms Manual to see your symptoms. Hope you feel better soon!