Best Diet Plan for Natural Bodybuilder

Hi Coach @Christian_Thibaudeau
It’s been quite some time. So I’m 43 years old, I’m 5’11" and weigh 240 lbs. I’ve lifted weights on and off for over 25 years but the nutrition side of things was never my strong suit. About 15 years ago I could have been mistaken for a bodybuilder. Now… I’m just a big guy. Recent health issues have made me realize that I need to pay closer attention to my diet. But I’m wondering, can someone go from having no structured diet at all to something like this right away? Or should I baby step into it by making smaller changes first? I’m probably in that category of elevated cortisol due to not eating enough and the constant starvation mode that comes with it. I thought I was doing “intermittent fasting” but I was probably just starving myself which made me just hang on to every calorie I ate. When I do take my lunch I try to do the chicken, rice and veggies. But more often than not I would just go the fast food route thinking that my time in the gym would undo that mistake. It hasn’t. Dinner was whatever carb heavy box meal could be whipped up in the least amount of time. I’m one of those that works out first thing in the morning, so I’m at the gym by 5 am and when I get home it’s a blur to get the kids ready for school and on the way to work so breakfast was a protein shake and a banana at best. Not trying to make excuses just trying to give you a full picture. Any advice would be more than appreciated.