TW: History of disordered eating

Hi all, hope you are well.

I am in my mid-30s and have struggled with my weight for over 20 years. It started basically as soon as I was put on the pill as a teen to regulate my periods - HUGE mistake by the way, there was a LOT they didn't tell me about health and fertility issues down the line. That aside, I went from being a very petite preteen to constantly struggling with my weight ever since then.

When I was 17, I went on a very extreme diet where I exercised for several hours a day and only ate crackers and drank lemon water. I lost a lot of weight, but yoyo'd immediately. This happened again in my early 20s, though not by choice. At that time I couldn't eat due to intense stress, and ended up losing 15kg in less than 2 months. It was effective only because I was literally starving, and as soon as I ate healthier, it all came back on and then some - so I am NOT recommending disordered eating by any means. I just have a history of falling into these traps, and I very much regret it. I feel it contributed to many years of repeated setbacks, hesitancy, and bad habits.

Since my early 20s, I have tried just about everything - working out regularly, eating better, keto, paleo, just about anything you can think of. Sometimes I get results but end up yoyoing back, and sometimes I never get results to begin with. I am relatively "fit" despite my size. As in, I am flexible, I can walk just about forever, and I am very physically strong. But I feel huge, especially within the groups I now associate with. I am constantly surrounded by very fit and healthy, feminine women, and I feel like a water tank sitting next to them.

I look back at photos from 10-15 years ago and I know at that time I hated myself, thought I was extremely obese, was promising that I would not let myself hit 30 without losing all that weight ... and yet when I look back, I looked perfectly fine then and have only gotten bigger and bigger. It's really causing serious issues in my life nowadays. I know I can't expect to have the body of a 22 year old in my mid 30s and beyond, but how do I stop regretting the way I treated myself then? I feel like I spent 15-20 years hating my body and trying everything to "improve" it, only to fail again and again.
I have kids now, and I want to teach them better relationships with themselves and with food. I need to lead by example, so I am making a change once and for all (I hope)!!

So my advice is thus: whatever body you have, try to appreciate it now, love it now, treat it well now. And keep doing it.

And my questions are thus: how do I get over this depressing feeling that no matter what I do, how hard I work, all my progress will eventually be lost? What has worked/not worked for you? What do you struggle with now as compared to when you were younger? Have you managed to make sustainable change for many years?