If there's a pattern that I've noticed amongst the people in my life who struggle with their weight is that they all have an emotional relationship with food. They eat not to serve their metabolic needs but to serve their emotional needs. They say they are counting their calories, but they aren't being honest with themselves about it. They can't make clear headed diet decisions because their feelings are so wrapped up in the act of eating.
100% this. I've been overweight to varying degrees for most of my life, but my weight has been at its lowest when I'm happy and highest when I have high stress or anxiety. Anxiety especially seems to lead to poor eating because you go into survival mode and stop being able to think long term, while loading up on food as if you were a hunter gatherer about to go through times of extreme food uncertainty.