Never, never, never, never give up. W. C.
I think that discouragement is impossible if you focus on two small ideas
1. Every small effort is already a victory. Victory is not a number in the distant future. Victory is feeling and being healthy today, now, because of a small effort.
2. You will not be happier because of being thin, but because you are healthy. Healthy is first in your head and this health, this control of self is possible every moment you select health.