@Greywarden You could try examining what is going through your head when you reach for food. This is what I was told.
When you stand looking in the fridge or cupboard to get something to put in your mouth, why are you doing that? What triggered it? Hunger, boredom, discomfort, stress, frustration, anger etc etc. Note that emotion. Is there a theme or frequency? If you wait five minutes, does the urge disappear? Can you deal with whatever caused the trigger. Can you use something other than food to deal with the urge?
Then you examine how you feel about food. How do you think about it? Is it a reward? Does it soothe you? Is it a treat? Do you think of it in terms of good or bad?
These require a mindshift. Food is none of these things, it is just food - fuel for your body. Some is healthy for you, some is less healthy. Aim for more healthy food, but it is OK to eat less healthy food, just not all the time.
Nothing is forbidden, you don't need to feel guilty or punish yourself. When you give yourself permission to eat anything, you lose the urge to eat foods you once thought were 'bad' or 'naughty', because now you know that food is just food.
On the self esteem side of things, you need to know you are awesome. You do brilliant things. You made a brand new person, that's really amazing when you think about it. You did that. Don't be ashamed of that. Embrace all the good things you have, a child, a man who loves you, friends and all the other things.
You don't have to like how your body is currently, but accept that is where you are at the moment and make peace with it. It is temporary and you can fix it. It won't be a quick fix, but you can do it day by day, kilo by kilo. Acceptance will help with the guilt and loathing, you don't need them, they don't serve any purpose. Be kind to yourself, it's a long road you're on, there will be bumps, but it will be ok. You can do this, one step at a time, keep moving forwards. You've got this.