I've got other issues with my neck which could have something to do with the pressure in my head, yet I didn't hit my head and the bump on my head is more present after I eat. After eating, I feel not well and sometimes have to "pass out" and litterally go to sleep at that spot, I cannot wait, I cannot keep my eyes open and not laying down quickly enough gives me cramps in my head, arms and legs. I have to pinch myself to find my way to the bed or the couch. I the past, I couldn't even make it from one place to the other without sleeping in the train, the car. In the summertime I even layed down in a park until the worst was over.
What could it be? Over time it got worse, with dizzyness and short time memory problems and not being able to think quickly and being absent amongst others, not always being able to retain more information.