It has to become habit. It takes a person 28 days to establish a new habit. So force yourself to do it for a month and it’ll just become part of your lifestyle. It’s a lot easier if you pick something you actually enjoy. I lift weights throughout the winter, and early spring, but I don’t like it very much, so I have to be disciplined when it’s time to start. During the good weather I rock climb, do a lot of hiking, ride mountain bikes, and go backpacking. I do enjoy that, so it’s never something I need to make myself do. I miss it when I’m not doing it. So the best advice I can give you is to find a physical activity you actually enjoy, and then make time for it. It could be basketball, tennis, karate, chopping wood, whatever. Try different things until you find something.
Routine is the only cure.
Turn it into a part of your lifestyle. I got my tennis such that it feels wrong if im not doing it regularly. They say it takes 90 days to make something a habit. Now working on zone 2 conditioning, and hopefully turning it into something more. Good luck!
eat good and exercise.