Since I've been on this journey which began February/2014, starting at 301.6 I've never quit, but I regressed to the tune of 60 or so lbs of regain.
Some of the mindsets that helped foster this were -
It's just one day...
Ooh is that on sale? (Looking at a trigger food)
Being letdown or elevated by a high/low weigh in have been triggers if it's bad I've felt like oh well today is ruined anyway and if it's "good" (better than expected) then I feel I have wiggle room to eat poorly.
Also success can be scary especially when we lie to ourselves that we don't deserve it, you absolutely do deserve to be happy, healthy and comfortable in your own skin. It's so important to be your own ally, guard and protect yourself from harm. I'm getting better at this.
Adding, feeling helpless around food or when I've gone long periods without eating, the truth is at 250+ lbs give or take 50 it's highly unlikely I will starve if I'm late eating dinner.
Helpless as if I don't have the power to refuse to eat foods that don't love me as well as I love them, you truly are in control of what goes in your mouth, it's not blaming it's empowering use your power wisely.