How to lose 35 pounds in 2 months?

ok so im 12 years old and i weigh 143-150 pounds.....YES I KNOW I AM FAT........ im 5`3 so i started this jillian Michael's workout video and it says lose 20 lbs in 30 days. but i think i gain weight again because i don`t have a healthy diet plan.....plus my mom doesn`t even buy the healthy foods i need.....CAN YOU PLEASE HELP ME LOSE WEIGHT...... AND PLUS CAN YOU GUYS MAKE A DIET PLAN FOR ME.....thanks ADELA :(