I have a bump on right side of back of head. When it first swelled up there I had a sharp like ice pick stabbing pain go from back of head through brain to front of brain. I first thought something had bitten me. I have had it for about 8 months. It goes away and then swells back up with sharp pain shooting back though my brain. My doctor said it might be a tick bite. She did a lyme disease test and it was negitive. I pick at it because it feels as if there is something under the skin. I also have be having spells like my vision goes blurred and very weak spells when I have this pain. Like I am going to faint. Do you have any suggestions what it could be?