Plz help with a girl problem...!?

I have a whitish discharge which is also brownish at times, and it stinks a lot. It is in considerable amount. It causes lots of itching and when itching stops, i have pains while urinating. Likewise when this pain stops, itching starts again. Its been going on for about a month. What could it possibly be? I'm 15 and how do i bring it up with my mom? She said its just probably urine infection and you must drink lots of water. Someone else said I have AIDS and will die within a month!! WTF? I'm totally confused!!