Concerns about myself

I walked for a few minutes today.  Maybe I shouldn't even make plans.  I never seem to follow through.  I was given a resistance band that I received from the hospital.  However, I have yet to use it.  I even have instructions that come with it.   I wonder what is wrong with me.  I want to be like these people who love to exercise.  They eat, breathe, and sleep exercise.  I just don't have that yet.  I feel down because I have the motivation, but I lack the drive.  That worries me.