Constant headaches early in second trimester?

I'm almost 15 weeks and early in the first trimester I had headaches, but I feel like they are actually getting worse. They feel almost sinus related; a lot of pain/pressure between my eyes and forehead. Sometimes I also feel it in my neck. At their worst I feel a bit dizzy and nauseous, and they don't seem to go away after a night's sleep. Anyone else experience these, or have any advice? Does this sound normal? At my last appointment my midwife noticed that my blood sugar was low, so I've been working to increase my OJ, milk and foods that will bring that up...are the headaches possibly related? Thank you!