When you choose to make a commitment you do it for a good reason, whether it be to better yourself or to help someone else. If you chose to do it, stick to it. Don’t give up on what you promised, because that is how you fail yourself. By not sticking you your commitment you are telling yourself you cannot do it, when you actually can.
A commitment is all about putting effort into accomplishing or maintaining a goal, when you give up on that goal you are giving up on yourself.