I hate exercising, but I do it religiously. I am 64 years old, and in the best shape of my life. Same weight (and weight distribution!) as in college, good muscle tone. I think three things were critical, for me:
1. Absolutely no soft drinks at all. Not with sugar, not with artificial sweeteners. Nothing. Just seltzer. I used to drink a LOT of Dr. Pepper, and was told that they were contributing to my frequent kidney stones. So I stopped cold turkey, 30 years ago. I've had, I think, two Dr. Peppers since then. (I try to avoid processed foods in general, but I'm not a fanatic.)
2. Find an exericse regimen that requires you to show up, on time, and be accountable to others. I want a trainer to tell me what to do, turn off my brain, and just do it. That external accountability is crucial. I could find crossfit routines online, but then I don't do them. (I tried that, early in the pandemic.)
3. DO NOT treat exercise as a priority. Because then it is subject to your other priorities. Instead, make it a habit. You don't schedule brushing your teeth, and it is never traded off for other activities. You just do it when you're supposed to.
When circumstances pull me away from my routine (pandemic, extended family emergency), I feel like shit. My joints get creaky. Certain muscles start hurting. I have no energy. This all goes away once I return to my exercise routine. I hate it, but I love having done it -- I feel so much better in general. The high point of my day is when I am walking OUT of the gym.