What Causes Severe Pain In Head And Knot On Back Of Head Post Injury?

im 35 yrs old and last night around 7:30 i was walking through my hallway and next thing i know im on my back and my entire head hurt. my eyes were closed and i had no idea what was going on but all i could think about was the pain inside my head, a severe pain that i have never experienced before. my chin was against my chest and all my muscles were contracted my arms were clenched against my stomach. it was almost like waking from a dream. i was confused and disoriented, when i finally got up it was like my muscles wouldn t relax. i have an enormous knot on the back of my head that hurts, i have a tingling on my head and it feels weird (i wish i could explain it) sometimes its like a pressure. my neck is so stiff that i can barely move it and there is a tingling between my shoulder blades. i feel slower and not right.