I learned very unhealthy habits from my family and even though I intellectually knew what I should do later on, I usually didn't do it (eating the right things, eating less, etc).
At risk of sounding like a broken record, the only thing that worked for me to change my habits was using positive affirmations - and actually, I noticed that eating right was the first thing that changed when I started doing them, and very quickly, in a matter of a few weeks tbh.
Since I started doing this, I've been eating right basically every day and it is not a chore. I don't spend time thinking about it. I just find myself rejecting things that hurt me and embracing things that make me feel good - in the case of food, that means I turned away from meat, takeout, fast food, junk food, etc. and turned toward a vegetable based diet that is well-balanced and I eat A LOT LESS. Like, it's shocking to think about how much I used to eat. I couldn't see it for a long time.
I look incredible for the first time since college, I feel great, and it takes no effort whatsoever. It's amazing.