Headaches? please help?

for about the past four months or so, i've been getting these really bad headaches, usually in the afternoon around 3 or 4. anytime i go outside and it's really bright out i get a sudden headache too but that usually goes away quickly. the headaches in the afternoon don't last very long each day, but it's pretty bad feeling and usually in the right side and right temple of my head. i find sometimes that after i eat something, the headache will go away, but other times that doesn't work. i don't know if it's just a coincidence, or what's wrong.. if they're normal headaches or something maybe worse.. i'm a little concerned because i know a friend who had a brain tumor when she was 11 (benign thank goodness) but that still worries me a bit. i don't like to jump to conclusions, but i'm a little wary. can anyone give me any clues as to what it might be or what i should do? no stupid answers, thanks. thanks to anyone who has advice/help!