I second and third the advice you've gotten above! Headaches are awful, and can be caused by about a million things...the good thing is, with a medical work-up, your doc would be able to narrow down a possible cause pretty quick, and lay out treatment options. Headaches can result from things such as vision changes (need for glasses, or stronger eye Rx), dental issues, they can be migraines, tension headaches, cluster headaches, can be related to hormonal changes (or hormonal meds, such as the pill, or hormone replacement therapy), thyroid issues...you name it. Another very common cause? Anxiety of course.
Once you see your doc, you'll have a much better idea what you're dealing with. Try very hard not to think the worst...like brain tumors, strokes, etc. THOSE, while they can cause headaches, are rarely the cause, not to mention, you'd have concurrent, usually pretty obvious other symptoms.
Let us know the result of your doc appt!
Have you seen your doctor? Best place for you to start. Once everything medically is ruled out than you can focus on working on the anxiety from the headaches. I get anxious when I get headaches in certain areas of my head. Pretty much any that arent in the back cause my anxiety.
Also if nothing medical is found you can try things like massage, meditation, exercise and other things to help your headaches and anxiety. My husband was put on Inderal for headaches and it worked wonders for him. I take it for tremors in my hands and for anxiety. So it is a very useful drug if it comes down to you needing to have a medication.
But see your doctor and keep us updated
The first thing you need to do is discuss these headaches with your doctor. I get the same thing and it's always a sinus infection, which can also cause the dizziness. Migraines are often on one side of the head as well. Since the pain is scaring you so badly......been there, see your doctor to get checked out and get peace of mind over this. Not knowing what it is keeps your anxiety going, see your doctor so you can put this worry to rest! Take care!