Last December 2011, I was wropping X-mas presents. For that I stepped on the chair trying to pick up a box on the top of the bookcase. Lost the balance and flipped over, 7 feet, to the floor on the back of my head. Pains stared next day. I was wripiing cold pad around my pains almost 24/7. After 3 month the pains decreased by 50%. I was huppy. But then I went to a dentist and had 3 X-rays. It triggered my head pains 24/7. I was back to cold pads.
I Had MRI: it shows "white substance" on the top of my head. Which a Doctor interpreted as "probably due to old age."
I went to 3 different Neurologist: 1st said nothing and asked to come back 3 month later. 2nd send to "Pain doctors" who are giving injections to decrease the pains. 3rd said "Only in 10% patients head pains continue for such long time. Lets wait for 3 more month."
Using just a common sense (one does not need to be a rocket scientist) to know that my pains continue (on top of my head) not by an accident: there are reason for that. Something is going on that is why I am not recovering. I took Tylanol and Aspirine, but there is no dent in my head pains from taking those drugs. Also, I tried some Vitamins and herbs for head pains. But, they immidiatly triggered head pains. So I stopped it. Plus, the Sun, heat, and coffee also trigged head pains on top of my head.

I appreciate very much any suggestions.
Do you have any suggestions?

There are internet sites such as neurotalk.com where you can discuss symptoms and treatments for long term concussion and TBI (traumatic brain injury) with others in the same boat. Read all you can on those two conditions. I don't think very many doctors, even neurologists, study brain injury very much.
Keep in mind that the brain matter itself has no feeling, it's blood vessels and outer nerves that are hurting. Hitting the top/back of your head may have affected your very highest vertebrae, which could cause referred pain. Autopsies of whiplash victims who suffered pain for years with no diagnosis have shown dried bruises (clumps of blood) pressing on the nerves coming out of the spine, and they didn't show on X ray.
You could also have had a cerebrospinal fluid leak out of the dura mater, the outermost of the protective layers around the brain. I wonder if that was the 'white stuff' on the MRI (I have no idea what it would look like on an MRI). There is a treatment for that... a patch, and some others.
I would go get the MRI and take it to a more respected neurologist. They have to release it to you. Of course that dr will probably want another MRI or a CT scan.