testicular cancer question... PLEASE HELP!?

ok so i woke up today & my balls hurt pretty bad. it felt like a mild rugburn or sunburn. my scrotum was & is fairly reddish but the hurting has gone away mostly UNLESS my balls rub my pants, etc. im really freaked out thinking i might have cancer, but im only 15. i looked up the symptoms & if i remember right they were: lump on either testicle that may or may not hurt (i didnt notice anything too odd) heaviness in abdomen or scrotum (not really) lower back pain (ive always had that) pain or tenderness of the bottom of the scrotum (yeah it kinda tender). my scrotum rubbed up against my computer chair in my room when i was changing clothes & it got reddish right after in the same spot but still. what do you think is wrong & what should i do?? (& PLEASE DONT say see a dr. yeah i know, but i dont have enough money). please answer soon & thanks