Hi. I am a thriteen year old girl, and I have been feeling not very good for quite a long time, maybe a few months or so? I don't feel particularly sick, but certainly not very energetic. It could be linked to the fact that i don't sleep well these days, which I'm also worried about by the way. At about noon today, while I was on the computer, I started feeling a dull pain in the back of my head, which slightly increased when I sniffed. I'm afraid I might have brain cancer, but I am scared to ask my mother to take me to the doctor as I am stressed about what the results could be; also, my mother is very used to me being a hypocondriac. I used to worry --still do, actually-- about whether or not I was going to have a heart attack at least twice a month. I also have OCD, which makes me "slightly" paranoid about any kind of serious diseases. I don't know, am I just stressing for nothing again or is this actually a brain cancer?