When you are rebuilding your eating habits, the best thing you can possibly do is to go in slow increments. Commit fully to a small thing and keep with just that thing until it is a habit.
The best habit to build first is to only eat junk food that tastes good.
Most people eat an astounding number of things that are bad for them and don’t even taste that great. TV dinners, candy hearts, sort of tasteless preservative filled crackers….
The best way to start a diet is by replacing crappy junk food with high quality treats.
Replace your Snicker’s bar with a high quality chocolate.
Replace your t.v. dinner with homemade macaroni and cheese.
Replace your hot cocoa mix with real chocolate melted into milk.
Replace your crappy freezer or takeout pizza with fancy pizza from a good restaurant, or homemade.
Replace your fast food burger with a sandwich.
Replace your quart of freezer burned ice cream by going out to the nearest ice cream place.
Replace your cheap, terrible beer with delicious beer.
There are many reasons this approach to dieting works. First, by increasing the quality of your treats, you are avoiding any sense of deprivation. Second, you cannot just mindlessly eat, because you have to go to the effort of getting the higher quality stuff. Third, you are breaking any mental habits that you have around junk food. Fourth, generally better quality treats have better ingredients, which means less sugar, preservatives, corn syrup, etc, and also more protein and vitamins. Fifth, a lot of the better quality items are kind of a hassle, which subtly discourages you from overindulging.