Hi-I am not a medical doctor, instead I am a veterinarian. I would see your physician, get a complete blood panel and be sure to have your blood pressure and thyroid levels checked.
Stress can cause severe headaches and there are many ways to learn to deal with this. High blood pressure and thyroid conditions as well as various medications and vitamin supplements can also be a cause.
Should you and your doctor discover that these are migrane headaches, there are various medications and natural remedies to consider.
Best Wishes
Dr Carol Osborne, DVM
I use to have sever headache for years, I was told by my Dr.told me to stay away from caffine. So I did and it really helped. I don't have them any more.
Just food for thought.
it sounds like tension or cluster headaches,all of which can also cause you to feel dizzy and sick,go to your doctors for a proper check up.