After 20 years of being very overweight, I've lost over 4 stone in the last year, and have another 4 stone to go. I also have health complications that make it trickier.
Something that really helped me was aiming for the habit of a healthy lifestyle more than for weight loss.
The book Atomic Habits helped me hugely with gradually improving habits in a way I can stick to. I was drinking two litres of coca cola most days, and drinking water before coke, and gradually learning to think of myself as someone who drinks water rather than coke, was transformative. I'm not doing a good job of describing how and why, sorry!
Food wise, I've learned more and more about nutrition and am gradually changing to a largely Weston A Price type diet, including lots of traditional foods and butter and fermented foods and offal. A very gradual shift has worked SO much better than the many diets I tried over the years. My taste buds are starting to change - I used to eat 6 creme eggs in a sitting and when I tried one recently I didn't enjoy it very much. It's improved my gut health and my energy levels, and saved us a lot of money too. I'd read some other books which disagreed with calorie counting (it's more about hormones) and with low fat diets (animal fats are actually pretty good for us, and instead I cut down on UPFs and sugar), and those ideas have really worked for me.
I've learned lots about Natural Movement from Katie Bowman. If you can't do cardio yet, don't worry. Just get up more. Every half an hour stand up, stretch as high as you can, look out of the window, then sit back down. Eventually work up to walking more - first just park further away in the car park, then build up until you're happy walking distances you used to drive, or wandering through the woods for an hour. Whisk an egg but hand instead of using an electronic whisk, or have a picnic outside so you sit on the floor, or whatever is realistic for you. Lots of small movements throughout the day will make a difference. I now squat on the floor for a few minutes rather than sitting on a chair - I'm still not doing proper cardio, but that kind of change has helped my fitness and balance and energy. Squatting isn't the best starting point though, of course, so much as just standing up more often.
Those three ideas have made such a difference to me. And halfway to my goal weight, i already feel healthier than at any point since my early twenties. And it feels sustainable (like this is who I am and closer and closer to the lifestyle I want) rather than sacrificial (like I can't eat what I want because I need to lose weight, which is how diets always felt, and why I couldn't keep them up).
There are three other things that have helped.
One was getting my husband to understand how important this was to me, so that he'd stop buying me "treats" that amounted to an extra 1000 calories of junk every evening.
Another was spending lots of time outdoors - nature is such good medicine for bodies and minds which are struggling.
And the third was taking up a craft that I could do whilst watching a film or talking to my husband or similar. Empty hands made me crave junk food just like they made me crave cigarettes when I was much younger. I've saved a fortune by getting round to mending our clothes, and I've made nice things in the mean time.
Sorry it's such an essay. But I wanted to pass on what has really helped me. My life is getting better month by month, and I hope yours will too.