A week and a day ago, I got pushed to the ground and received a humungous bump on the top-left side of my head. That night it swelled down a lot, but the next day I almost fainted for the first time in my life. Since that day, I still have a bump, I have a great lack of focus, and sometimes feel a mild pain or numb/cold feeling in the spot of the bump. Is this a serious head injury?