Can i lose 90 pounds in 5months Im 14 ?

Hi my name is carmen and im 14 years old and i wear a size 18 some times 20. My height is 5 5 and i dont know how much i weigh but i do know dat i want to lose weight and get healthy for me and my family...So i just want to know will it be possible for me to lose 90 pounds in 5 months and does anybody know how much i might weigh....???? Please help me..?!?!