Whatever you did to finally achieve sobriety, apply that to weight loss. There's no trick to it other than consistency and commitment, but you have to do battle with your own mind. Seems like something you have plenty of experience with and if you had the mental strength to get sober then you definitely have the mental strength to lose weight.

Try to remind yourself that you're in charge. That means stop telling yourself that you tried a bunch of things and nothing worked, when the truth is that you tried a bunch of things that you gave up on. Admitting that you haven't tried your best feels shitty in the moment, but in the grand scheme of things it will make you feel less trapped and more in control. There is some trial and error involved in finding what works for you, but when you realize something isn't sustainable, don't use it as an excuse to stop. The only solution is to keep adjusting your strategy until you dial it in.