I dont know how to make it stop.
That statement is the key to your problem. You DO know how to make it stop. You've already done it. When you start to say things like I don't know how to do something or other, that's the opposite of an affirmation. That is the way you convince yourself repetitively that you can't do something. That is simply not true.
You need to stop saying that to yourself and look at what has happened to you and how you lost the weight. You didn't lose the weight from having the surgery. You lost it because you changed your eating and your habits. You lost it because you loved the person you were becoming.
That voice in your head is a problem. That voice in your head is your eating disorder and unfortunately no amount of surgery can cut that out. So what you're really struggling with is a battle of will. If you listen to that voice, if you let it get stronger by repeating its negative message, you will gain all your weight back and more.
You definitely do need a support group but you don't need to talk to somebody who has been through what you have been through. It's possible that if you find someone like that, you will enable each other and just go back to your bad old ways. You need to read success stories and you need new things to tell yourself.
The ability to change this lies within you. If you got to heaven and saw all of its beauty and found unspeakable joy, would you ask if you could please go to hell instead? I think that reclaiming your life and getting down to a size you love and health you never had before is heaven.
You're the only person who can fix this, but guess what? You can! Stop pitying yourself and look at the reality of how you were eating before you started to gain back the weight. Then go back there. Do what you know works.
Self-pity is the most dangerous thing you can allow in your life. It will stop you from reaching every goal. Self-pity is the same as saying I don't deserve this. You do! So get back to the way you were eating six months ago or a year ago and as soon as those pounds start to come off, congratulate yourself and keep on going.