Motivation comes from within. If you like what you are doing, you will be more apt to do it. Meditation is not for everyone. I believe that there are other tools in our world that will help us de-stress just as good as meditation, such as walking in the forest, sitting next to a stream and listening to it go by, fishing, arts and crafts, watching a baby sleep, petting your pet, etc. So, do not force yourself to meditate, it won't work and you will just be more frustrated with the practice.