help me get confidence

I'm 16 5'4 and I weigh like 270 lbs most of the weight is in my hips and butt because they are quite big both of them I don't really have a gut but I want to get rid of it I work in a barn so I'm always active and I don't eat much I don't eat breakfast or lunch and I eat a small dinner I struggle with body confidence even when my boyfriend tells me I'm beautiful it's still hard to believe him even though ik he loves my body does anyone have any tips on loosing my gut and gaing confidence?