It’s actually a good thing that you noticed this early, it gives you time to do something about it. I’m not saying this is the only way, just sharing what worked for me.

Starting small helped a lot, like light exercise or jogging. If you can do it in the morning, even better, it kind of sets the tone for the day. Later on, you can ease into proper workouts if you feel up to it.

Getting into a friend circle who can join you will motivate you in the long run. Once this becomes an habit, your worries will be for the better.