Hi! I need to lose 20lbs but struggle to keep on track

Hi! I know I need to lose weight. I have tried and failed so many times that I have convinced myself that I can’t do it. I love seeing other people’s success but I think they must be different from me. Ridiculous right?! I am 54, recently separated with two children and a dog. I am a pretty positive person generally but weak when it comes to losing weight. Any help on the journey would be appreciated!

Thanks!