What Causes Headache And Dizziness?

I have been having these headaches since the summer. they come on go and now Im having them everyday. Iv seen my doc and every test they give me comes back negative. Right now Im dizzy. Yesterday I had a headache until I went to sleep. I do take tynol. Im waiting for a head doc to give me an appt. In the mean time, I dont want to keep having to take meds just to feel better. I have no high blood pressure, and right now they think its stress or anixty. I also had a nosebleed out the blue last week which triggered a headache. Im scared I may have some type of tumor.