Any advice (13.9 bmi 😬)

I’m 16m, 6’1 or 6’2, and 105lbs

I’m at my dads for the summer, and unlike my mom, he actually is trying to do something about my weight and just by doing that (I’m not even consuming 1000 cals a day) and I was still able to gain 5 pounds in 2 weeks

It’s in my daily routine to either feel like puking, even when I’m hungry I can’t eat a lot, my dad got me low THC high CBD gummies and I hadn’t eaten all day and I STILL barely finished my plate, a lot of times I’m so hungry that even looking at food makes me feel unwell, even when it’s anime food, I drink 2 Dr Peppers and a milkshake a day and that’s most of my daily calorie intake, I also have a genetic disorder which makes me lose calories faster due to how I walk so I kinda need advice