So i'll be meditating and suddenly a trigger thought will occur. Or i want to itch a body part really badly, but i resist. Then i will feel this surge of 'energy' run through the tail bone up to my Occipital area. I feel this generally within that area. Leo called it, "like two plates colliding." I've been feeling this pretty much every single meditation session I've had so far (a bit over 2 months now). What is this?