Have you already started to get discouraged? Don't let yourself get into the mindset of "Well, I've only completed half (or less than half) of my daily to-do list so I should quit."
When babies start to walk they fall down A LOT at the beginning. Do they give up? No. They get up and try again until that seemingly elusive moment happens. This needs to be your attitude about change. Take each day and even each hour as it comes. This goes back to keeping your focus. It takes 21-30 days to create new habits. Permanent change requires that you get rid of the old habits and you make new ones.
Think of Dory from Finding Nemo when you are tired or discouraged. Regardless of what situation she finds herself in, Dory recites in a little sing-song voice, "Just keep swimming, just keep swimming."
Bonus idea: Look back over the day and determine where things fell apart. Was it anything that could have been prevented? If so, how? Perhaps you should have planned better for the day or overslept. How could you change your schedule or how could you have handled things better?