Every time you make a decision or commitment and follow through on it you are building character, integrity and trustworthiness. In return this makes you stronger, happier and calmer.
Pick one small thing to do every day to improve your health or fitness level and actually do it. By starting with something physical you can experience tangible results that will fuel all of your goals. It could be drinking a glass of water in the morning before you hit the coffee or my favorite example, flossing. It may not seem like much, but you are subtly practicing discipline, establishing trust in yourself and your ability to follow through on commitments. These are the necessary ingredients for accomplishing any goal.
When you decide to ramp it up with a bigger commitment, your sense of self efficacy will assure you that you are up to the task and you will be more likely to succeed.