I've lost 9 stone so far, and I've still got another 6ish to go.
What I've discovered is that there wasn't any one thing that was making me that fat, it was a collection of things. So my solution had to be a collection of things.
I started by changing one big thing (stopping full sugar drinks) and once I achieved that, something I thought I could never achieve, the successes snowballed.
I can't say it's been a smooth journey, there are times that it has taken over a bit too much and other times where I've given up a bit and started to relapse towards old habits one by one.
In terms of the mental side of it, I've done a lot of work in reducing my stress and taking up hobbies that bring me real joy. This has been life changing in ways that go far beyond weight. But it's helped fill the void that food was being used to fill. It's also been a lot about putting myself first, enjoying my own company, reducing my dependence on relationships that were leaving me feeling wounded which I was soothing with food.
In terms of practical habits - you will know all of these already - Sugary drinks, sauces, butter and oils, eating enough vitamins, minerals, protein, fibre, meal planning, having healthy snacks within grabbing distance, limiting empty kcal snacks etc etc. But the big work is in the mental side which has mainly come from self help and I see my (private) counsellor every couple of months for a catch up - but previously I did have a couple of years of seeing her fortnightly which helped me to ditch a toxic relationship, deal with some of my issues and get into the headspace to make the mental changes.
I have done mine without any injections or drugs (if I could afford it, I would and it's taken 18 months so far. I do get frustrated with how slow it feels but that's mainly because I have compared my journey to too many people's online journeys and remember it's always the most extreme (fastest, most lb lost etc) that get the most views and so these are not typical results.
Mostly it is down to a lot of self reflection, being honest with yourself, sitting with uncomfortable feelings and working out what you need to change, making changes beyond diet to help fill needs that you might be meeting with food, having a cast iron organisation system for meal plans and food prep, and having a lot of self compassion.