Dreaming of being behind in dreams is often an indication of procrastination and having to catch up on work. Procrastinating is a result of poor habits that leads you to eventual failure. Try your best to root out the poor habits, and establish good habits. If you are often ahead with work, or put in the extra hours, you would most likely not need to catch up. Start to devote more attention and time to what is important rather then waste the finite amount of time each and every person has.
Learn to deal with procrastination, and you will never have to catch up from behind again in your dreams.