I need help

I am a 4’9 person who is 168. I was never this big I was fit in high school and was 120 and since I graduated high school 2017 I moved in with my boyfriend and gained so much weight. My mom keeps telling me to lose weight cause she’s not comfortable seeing me this big and that I look uncomfortable and doesn’t want me to look like my aunts (all 5 of her sisters) are big people. She telling me to go on a diet or go do surgery it’s the best way to go. I also wore a crop top twice to her house and she made me change one time cause I made her uncomfortable and my little sister boyfriend and my little brothers girlfriend were there. The other day I wore a crop top and my dad and mom asked why I wore this it doesn’t suit me cause I’m fat while they let my little sister who’s skinny wear those stuff and I said I’m beautiful and sexy and kept saying that and my mom said I was annoying on that.

What should I do? I try to talk to everyone but nothing goes my way. I need help.