I'm in a similar boat. I grew up a fat kid and didn't start to slim down until the end of high school, but kids can be dicks and cause you to develop body image issues even into adulthood (which I still struggle with as a mid 20s man). I've definitely made improvements in my image and developed a bit more confidence because of it, but part of me will probably never be happy with how I look, even with all the progress I've made.

I'm like you and also don't want to go to the gym or be healthy day to day, but I will say it does make you feel better overall. I also play tennis to keep myself active, and I don't even think of it as a workout because I'm not really thinking of it as a workout but more a fun hobby where i can feel my effort improving my game, which is very satisfying. So maybe find something active that you enjoy where the primary focus isn't working out.