Make exercise a priority in your life. Write it on your calendar or include it in your scheduling program. If you wait to do it until you have time, or when you think of it, you will not get it done. You have to be consistent in order see significant results.
To build up your speed when running, try increasing the speed of your stride instead of the length of your stride. Your foot should be aligned under your body when running, not in front of it. Proper propulsion should be achieved by pushing off with the toes of your rear foot.