Organize your time. You can set a budget for your time just as you can set a budget for your money. Since you're trying to reduce worry rather than increase it, go into this process with a focus on maximizing your personal time, rather than cramming as much as you can into each day.
Set a sleep schedule. Stick to it, even on weekends. Give yourself a one-hour target window for bedtime in the evening, and set a strict time to get up in the morning. Be sure that the space between your bedtime and the start of your day gives you roughly an hour more than the amount of sleep you actually need, so you won't lay down and start worrying about whether or not you'll fall asleep on time.
Take care of tasks at the same time every day. Plan time for daily hygiene, commuting, work, shopping, eating, and chores. Add in time for anything else you do most days, such as homework, exercise, or an active hobby. Put them in a specific order that works for you. All the time left over is your free time, to use for relaxation or whatever else you want.
To maximize your free time, try to combine trips outside the home. For example, you might plan to go shopping on your way home from work, to save the extra trip.
For many people, an irregular work schedule makes this kind of budgeting difficult, but you can still plan to work around your schedule in the same order every day, and just shuffle the times.