How to explain my symptoms
 

I think I have finally figured out the cause of some of my problems. When I try to go for a walk or do much of anything, after about 25 minutes I get pain at the base of my skull, nausea, feeling of heaviness...if I continue to walk the pressure builds in my head and the fatigue worsens.

I usually try try to lay down and ice the back of my head then.

Is this an occipital headache? How can I fix this? No one is treating my neck. Up until now I was having a difficult time explaining this.

Su seb

Just my opinion
 

It sounds like a neck issue to me. I used to have similar feelings as you before seeing my PT. I highly recommend seeing a physical therapist trained in the Mulligan technique, if you can find one. My therapist cured my headaches just by making a gentle adjustment and then had me do exercises to strengthen my upper vertabrae, which helped a bit with my dizziness.

You could get a CT scan of your neck, but my pt helped me without seeing one. She could actually feel what was wrong with my neck just by feeling it. I had a gap between my C-2 and C-3 vertebrae in addition to being very unstable in my upper vertebrae. Later, when I requested my medical records from the hospital after my last accident, I found that the CT scan I had at the hospital showed this abnormality, but no one told me about it! I was so mad! I was in pain for 2 months trying to figure out what was wrong! I have no faith in emergency room doctors.

I'm not suggesting that you have the exact same problems as I, but just that a whiplash injury to the neck seems likely!

I have a similar problem and was told I had a cervicogenic concussion as well as a brain one.
I have been getting neck treatments (accupuncture, stretching and strengthening). I just got my MRI results back and it shows some problems with the C5-7 discs...some tears, etc.

It sounds like you have a neck injury too!