Honestly, diets don't work. You need to make a total lifestyle change. I say this as someone who lost 10 stone. I tried every diet out there, I have PCOS so also tried keto which did work, but I knew I couldn't low carb for the rest of my life.
I stopped buying junk and always had fruit and yoghurt for something sweet as I can't cut out sweet stuff. I also losely follow the 16:8 style of eating.
Dieting for me was always limiting myself and then expecting once I was slim, I could just go back to it. I couldn't understand people who had a biscuit with their tea and not half the pack or a slice of cake and didn't go back for another one.
I don't know if this is helpful but I just had to change my relationship with food and that was the hardest part. It was an emotional crutch for me, a way to reward myself or console myself. I am not perfect, I still eat too much sweet stuff sometimes, but I stopped hating myself for it, wrote it off as a bad day and started again.
In addition, please avoid the low fat stuff if you can. Imo much better to have some full fat greek yoghurt with berries for breakfast than a muller light after dinner