What I really need to know about fitness/diet/exercise/perseverance, I learned during 12 weeks of what, at that time, seemed like pure Hell.  USMC Boot Camp is a true "controlled environment".  You sleep, eat, run, jump, relieve yourself, you name it..........when you are told to.  At 19, most people (myself included) are or were undisciplined.  That gets fixed really quickly with 3 combat veteran Drill Instructors screaming in your face.  You run until you are tired......then you run some more..........then you run until you feel like you will drop.......then you keep running.  You then get to do an obstacle course, then sit in a classroom and try to stay awake.  You're up before dawn.  You sleep like never before.  You eat a lot during your meals.....you get no "snacks".  You don't have a couch to sit on or a TV to watch.  The upshot is that you are working hard, sleeping well, and eating plenty.  Your body responds.  I went in at what I thought was a relatively good weight for me.  I came out 15 lbs lighter, much faster and stronger.  Not everyone needs to go to Boot Camp, but you can approximate the results.  Remember the three important factors.  Work hard.....plenty of exercise.........sleep well (made easier by the exercise, I've found)........eat PLENTY of good food.  Skip the "snacks".  You don't need 'em.  Be patient.  Keep at it.......Don't set an artificial date to "achieve your desired results"  That sets up a time in your mind at which you will want to return to your old behaviors.  If you change to this lifestyle, You will get results!  Go for it.