Amy, remember this:
Remember today. Remember the day that you were walking at the track, training for your first 5K that is just under 2 months away... remember how you knew you needed to jog...and so, you did. Remember how you could only jog for 45 seconds at a time and then had to walk for a long time because those 79 pounds of extra weight are hard on your legs. Remember that you felt like crying...that you didn't feel powerful. Remember that you prayed as you walked...that you asked God to make your legs strong and to make them able to carry you so you could jog without so much pain.
When you get there, remember this.
When you reach your goal weight and people ask you to tell your story..........don't forget these parts. And don't forget to remember that it wasn't in your own strength, but it was God.
Use the doors that He opens for HIS glory, and not your own.