The big girl

I’ve done the diets, I’ve ran miles upon miles, I was even in Air Force ROTC last year working my butt off. But I’m still the big chunky girl. Currently trying the Keto diet... praying for a miracle. I work out 3-4 days a week, eat healthy, etc. what am I doing wrong? Ive tried diet pills, vitamins, supplements, protein powders, hell I’ve even tried prescription pills. But at the end of it all, theres either no change or I gain weight. Just feeling hopeless.