i’m 15, 5ft 8in and in July i weighed 9stone 9 and now i weigh 10 stone 9

so my family visited this weekend, and over winter / christmas my diet hasn’t been the best (lots of sweets, chocolate, junk food etc). this caused me to put on a stone in weight. i am still in the healthy weight range for my height. however, my family decided to shout at me, telling me that my thighs are huge and my butt is disgusting, my belly is so fat. i’ve always has big thighs and butt and not a perfect flat belly, and i understand that i have put weight on, but now my mum is forcing me on a diet : i can only eat the things she gives me (fruit, salad, cereal etc). i understand this is normal for people to eat, but i was just trying to gain body confidence and now it’s ripped away from me and i hate myself again. i don’t want to be fat so i’m doing what my mother tells me. what do i do?