Age 15 and diagnosed with cancer?

hi everyone! my name is Bridget and im 15 years old. as you can guess im just a kid and im scared to death right now. last month i found a lump in my and i told my mom who immeadiately took me to my doctor who brought me to another doctor. and after many tests they found out it was breask cancer. stage 2, then the next time i went, it was stage 3. i have another appointment in two weeks and im terrified. i have nightmares of losing my hair and people poking fun at me. i always wanted to be treated like an adult by my parents and now more then ever i want to be a kid and just live my life without any worries. im asking anyone out there who has or had cancer or knows anyone who has or had cancer to help me... not money or anything, my parents are orthodontists and have that covered, but i need advice and some support and real facts from people. im to afraid to look online because i dont know what info i might find.