I've ranted before about becoming "food adults" by accepting where our food comes from, that meat is from animals we kill from food, that eating constantly from restaurant menus is infantilizing, and that real change comes from taking charge of your life. While these are critical steps to changing your food life, the opposite principle can also help: treat yourself like a child.
When we were children, we did (or didn't do) a lot of things because there were rules. We didn't think about most of those rules but they certainly allowed us to do the important stuff of childhood like playing and feeling safe and not agonizing over whether it would be ok to eat a bag of doritos at 10:30 at night. The sheer number of food cues and stimuli in our society make it very hard for adults to continually make better choices, and it can help to imagine you have a set of rules to follow like you did in childhood.
Any time you create a rule, you place a protective bubble around yourself. It can save your will power for another fight because the rule takes away the choice, just as it would for a child. Rules that you impose on yourself have the power to be as comforting as the firm hand of parental guidance. It's when we face infinite choice that no choice seems to satisfy us.
People like to believe that obesity is a morality issue that can be fixed by stronger strength of character and more will power. While I do believe that is a dead-end way of thinking for the most part, there is something to be said for will power - but not in the way you think. Will power IS important, but the best way to strengthen it is NOT to use it more often. It's not like a muscle that gets stronger the more you strain it. It's just the opposite: your will power gets stronger when you use it as little as possible. If you can make some changes in your daily life that take the burden off your will power, then your will power will be stronger when you really need it, in those situations where you cannot control the environment.
You can change your environment in two ways: make your home and work as stimulus-free as possible, and create rules. I have 4 children and a partner that eat things I choose not to eat. Some of the things they eat I do not find tempting, such as gluten-containing products, cereal, and popsicles. I can keep those things in the house without spending huge amounts of mental energy resisting them. If I have chocolate in the house, on the other hand, I will think about it all the time.
Rules that I follow that save me a lot of mental theatrics: no eating after 7pm (this saved me from eating junk food at the Predators game on Saturday), no gluten EVER, no snacking (eat a meal if hungry, otherwise snacking is for mental, not physical reasons). Some I have used in the past to address particularly thorny issues: no sugar, no eating out.
You can't fix everything at once. Instead, pick one food issue that you really struggle with and try to create a rule for that issue. Pretend that rule is unbreakable and is as strong as you imagined your parents to be when you were young, because sometimes when your parents said "because I said so", they may have been making life a lot easier for you, and you can do the same for yourself.
Second, make sure your primary environments are not encouraging failure when it comes to your one issue. Is your home a place where you can free your mind of your struggle with this issue? What about your work environment? If not, why? And what can you do about it to stop blaming yourself and start helping yourself?