Are you concerned that you will be unable to do all that you need to do today? If so, apply the “divide and conquer” principle.
To conquer your work, learn to divide your day into the separate jobs that must be done. Then, concentrate your whole attention on the one thing you are doing. Refuse to think back to what you have just finished or ahead to what comes next.
Jobs can be handled wisely and well on a one-by-one basis. Those same jobs would be overwhelming if looked at all at once. You will work with a sureness that leads to success when you divide your work into separate tasks. This is the way to achievement.