I can't get to sleep until about 1 or 2 am?!

I sat in bed last night at about 11:45pm after staying up since 9pm, and I simply could not get to sleep. I tried everything, turning off the nightlight (I'm nytophobic, it REALLY has a HUGE effect on me) sitting there with my eyes closed, just sitting, but I could not get to sleep. It was about 2am when I managed to drop off. I have had thumping headaches in certain areas of my skull today, and feel quite full (maybe not as a result of the lack of sleep) and a little bit sickly. I am really tired, and according to Lucy S, a girl in my class 'grumpy all day'. I have also noticed my left armpit aching for some reason. Do you know what this is, and how to cure it?

P.S I am eleven years of age, and cannot take any pills.