That's probably because dieting isn't healthy or maintainable. You should actually do a lifestyle change.

Dieting can help if you are overweight but aren't gaining anymore. I has been stuck at around 259 for years. I dieted for year and lost 100 pounds in the first 6 months. Of course it slowed down after that but after I stopped I have maintained my weight for another year so far, minus gaining and losing the occasional 5-10 pounds. Going to to it for one for round to loose another 20-30 pounds but maintaining your goal weight isn't as hard as a lot of people project it is as long as you don't overindulge all the time. If you can think of sweets and deserts as once in a while treats, it should be achieve able as long as there are no underlying medical issues. The hard part is losing it in the first place. Of course I'm talking only of my experience.

my mom used to force me to diet lol

He probably wrote that because he said he wasn't far from being clinically obese...

moms are people too they might not always be right but they worry none the less. she can't be that bad considering she raised to have the cairity self control to diet (hopefully a healthy diet)