Do I have a yeast infection? ( girls only please!)

I’ve been itching down there for a few days now and have some kind of white/yellow powdery stuff on the skin flaps of the vulva (I think that’s what it’s called.). The discharge is whitish and a little yellow and sort of thick. When it’s white it just looks like egg whites. My mom says I have a yeast infection and gave me some cream to put in. I tried putting it in but it hurt! Is it supposed to hurt? I followed the directions and everything but it doesn’t feel like I’m doing it right! This is my first time to put anything in and I’m really scared! It’s my first time having a yeast infection and I’m only 13! Do I really have a yeast infection? My mom says she’ll take me to the doctor only if I can’t use the cream and I just want to take a pill or something easier! Help?