I'm no expert, but if your neck was so bad you were dizzy it would show on an MRI. X-rays are of limited utility here as they can only show the bone, really. Almost everyone as they age shows disc deterioration and misalignment, if such a thing actually exists, but that isn't usually the cause of pain. If it's so bad it's impinging on a nerve, that could explain the leg numbness, but that would be from the lower back or hip area and wouldn't have anything to do with dizziness. Surgery when you don't need it solves nothing, because what would anyone do surgery on if your diagnostics don't show sufficient impingement anywhere? I also don't see how a chiropractor can fix dizziness unless, again, you have a severe neck problem. And the person to see for that isn't a neurosurgeon necessarily, it might be an orthopedic surgeon. That being said, there are a lot of things that can cause vertigo, including Mineire's ear, diseases in the inner ear, medications, anxiety, etc. I would focus on the vertigo and probably, whch is what I always say, if your current docs can't fix it, find better docs. For intractable problems, docs created the Mayo Clinic and Johns Hopkins and University hospitals to work in teams and do better medicine, and maybe it's your time to go to one of these places. Peace.
Maybe find a Feldenkrais instructor?