What Causes Severe Dizziness With Headache And Nausea?

Hello - I have been experiencing severe dizziness with head ache for the past 3 months. I went to the doctor and he thought it was from coming off of a cold and gave a prescription to help with the dizziness. The doctor visit was 2 months ago and the dizziness and head aches seem to be getting worse. I had a MRI in December and it come back clear. I have switched birth control methods during these months. I was on the mirena, but I felt it was causing the headaches, so I had it taken out and now I am back on the pill. I also am noticing a smell to my urine in the past couple days. I m just so tired of feeling dizzy, nauseous and having a head ache. I have 3 kids that need their mom back. Any help would be greatly appreciated. Thanks.