What is happening to me?

I get these piercing headaches, my body goes rigid and starts shaking. i feel pain and numbness in my extremities, and my vision starts to black out. All the VA has been willing to tell me is that its not a seizure. But its been happening for 8 years now and I still don't know what it is. It feels like a spike being driven through my brain. After the attack my body is very weak and sometimes has temporary paralysis is some regions of the body. It hasn't killed me yet but it certainly doesn't feel like a good thing.