The muscles in the neck, which are around the spine, have sensors which are used to maintain balance. If the neck muscles are asymmetrically contracting, this may cause dizziness and headaches. You should see a neurologist who can examine you. You may then need a MRI of the cervical spine and physical therapy. Good luck.
I am not a doctor or anything, but it sounds like you need to get an MRI taken of your neck. I had similiar syptoms (symptoms) and the MRI taken revealed a couple protruding disc and a Osteophyte(bony outgrowth from the neck bones) and other things that I still can't get answers to. Just make sure you get a good doctor, as I have yet to meet mine. When I go in I only see the doctor's assistant that does not know how to answer my questions.
My systems: Dizziness, hot sensation in neck when bending anyway, feeling of falling over, ringing in ears, headaches (frontal & behind the ears, tingling of hands and sometimes legs and face and off-balance with severe neck pain every 3weeks(can't move it-locks up). I hope this helped you a little.