I hate my body as a 15F but dieting and working out isn't working and im scared I won't be able to lose weight and ever date. Am I overreacting?

I am a 15F and I am about 260lbs (119kg) and I hate the way I look. I wouldn't say im excessively overweight but larger than normal and its making me hate my body. I have tried many different diets and exercise for years now but I have barely lost any weight and im scared that im not going to date someone because of my size but I also feel like im being dramatic. Im sorry I just needed somewhere to vent.