Time, gentlemen, please. In the view from rigorous honesty and no mental laziness, there are four concepts in time, past, present, future, and never never. We can control and modify our beliefs. As I recall from an English in the classes that I did not sleep through, some words belong in each phase of time and others do not, but the names escape me. Also there are words that have negative connotations if not definitions.
Discipline is one of those words. It implies that some rule set for future events did not occur, an expectation, and now, the past event failure is being visited upon us currently. Cannot do anything about it except take the abuse, even if we are doing it to ourselves, as in self abuse. It is the expectation that is out to lunch.
Self control, however, is in the present, and does not step out of the present tense. We can lose self control, as the desire to ____ (eat) is too large, and we can work on the desire to lessen the desire, or increase self control for the next time. Change only happens in the present. No guilt, no blame, just a desire which is beyond our direct and absolute control got out of hand. Now we need to live with the consequences.
Hope is another of those future looking words that create expectations without a real plan how to achieve the plan. Plans must not only be necessary but sufficient. There in lies the problem. Necessary and sufficient. It is the sufficient part that is our downfall. Self control allows for less than ideal performance, it can be better than last time, and still be a success. No expectations, no failure.
Buddha said something about expectations being the cause of unsatisfactoriness. Epictetus said some things are up to us and some are not. If we value that which is not up to us, we are in for misery. Oh well, life of some form, will go on.