It takes practice, if you are buying a lot of junk food, just say you are "only" getting the Doritos. When I was craving sweet stuff, I would buy Popsicles to overcome the craving. Popcicles are way less in calories than cookies, doughnuts, or cookie dough. Reasoning with myself in steps helped me deal with the overwhelming urges to gorge myself on junkfood/beer/pizza. It's taken me about 6 months to be able to just eat my staple (which is currently egg whites). I have cheat days, but I'm still losing weight (288 -> 246) I'm trying to get down to 160, but I don't know if that is realistic since I am 6 foot 1 male. It's going to take time, because you are building some new habits, and changing not just your perspective, but also the default settings of your body from eating whatever you wanted to. Its a victory that you have started, now whats going to be your next victory? Eating less one day? Eating less two days? Loseing that first 10 lbs? Seeing the numbers on the scale was a big motivating factor for me, actual real measurements of my victories piling up. And you can be the same way, it becomes easier, and you can do this. Just take your time, measure your calories (i try to stay under 1,000 most days) and weigh yourself. Find something you don't mind eating thats low in calories, and eventually you'll treat eating like breathing, it's something you have to do to stay alive, not something that has to be amazing every single time because you have access to it. I mean, just because you CAN have anything you want doesn't mean you should.

Good luck and keep up the hard fight.