Summarize this article in one sentence.
It's pretty unlikely that you'll reach your goal immediately; focus on making progress. Most positive things just take time and feeling grief can cause you to move backward on everything you've accomplished. Look at what you have already finished and compliment yourself on it. After all, you are that many steps closer to completing your mission. It is completely normal to fall back into old, comfortable habits, even if those habits make you unhappy. The important thing is to identify when you have fallen off track, and then immediately get back on! Don't let one imperfect day throw off your whole plan. Sometimes you might fall off track for a longer period of time. Maybe something unexpected happened or you just lost your motivation. Try to remember the first time you decided to make a change, and remind yourself that if you were able to do it once, you can do it an infinite number of times. Starting over is not a failure, but giving up is. Sometimes we are more vulnerable to setbacks after we've already made quite a bit of progress. Don't let any progress you might have made be your excuse to go back to square one. Always be conscious of your goal and where you are on your road to achieving it.  This is another scenario in which keeping a journal might come in handy. Keeping track of your thoughts is useful for maintaining awareness, especially if you feel like you are losing your motivation. Mindfulness is a great technique for reducing the stress you might feel due to a lot of changes happening in your life.  On the other side of the coin, be aware of situations that cause you to dwell on the past and focus your energy on moving forward. If you bomb a presentation at work, make a list of all the things you want to remember for next time. Remember that staying out of a rut is a continuous process. An actor who makes one bad film isn't necessarily a bad actor, just like a person who has one bad week doesn't necessarily have a bad life.

Summary:
Don't be too hard on yourself. Get right back into your new routine. Practice mindfulness, or living in the present.