Making changes can hurt -- both literally and figuratively. If you're not yet able to wrap your head around helping yourself, skip an unhealthy snack or push through a tough workout for your future self. In the future, you'll look back and really appreciate the *you* who changed your life.
Someone inspired me to get past the initial struggle by quizzing me. "How do you move Mount Fuji?" -- One pebble at a time. If you can just get out there, beginning with the action of "doing it" as your only expectation, you will begin to move those pebbles. And soon you will gain momentum.