So how do we 'fix' this problem?
Step One: Identify the old habit pattern. Jim Rohn once stated "A person can never leave a place they have never been." So identify your struggle, accept it and plan to change it with a new/improved habit.
Step Two: Put up a 'No Excuse Zone' sign. Not a real sign, but a way for you and your support team to know that you are sick and tired of being sick and tired and that you are ready to do whatever it takes to achieve your goal. No excuses means: you are never 'too tired' to exercise. It's never 'too late' to plan tomorrows meals.
You must stick to these steps and consciously and consistently take action in forming your new habits. New habits (over a period of time) equal a new you.