OKAY, it's bad analogy time. You talk of this as a long journey. If you are only focused on the far off horizon, you are going to stumble and fall. Right now keep your eyes on the ground right in front of you, step carefully, and just keep moving ahead. It's a one step at a time thing. If you misstep, get back on the path.
The road may be long but if you don't start, you will never get there.
Another member (Keriann) has a great tag line that sums it up. You don't have to lose 79 pounds. You have to lose one pound- 79 times. So work at it one pound/one day at a time.