The organic acids test sounds like a good idea to me. Might shed some light on what is going wrong with your neurotransmitters (other then benzo withdrawal).
As for the skull presure, are you sure you're not just experiencing bad tension headaches?
If you're in an incredibly bad way or possibly antioxidant depleted, I suggest you give Miracle-Mineral-Supplement a miss. Stuff can be incredibly nasty if you're not feeling up to it.