In German language, there is the beautiful expression "seinen inneren Schweinehund überwinden", which amounts to "to overcome one's inner pig-dog", and vividly describes the feeling of surpassing the barrier of discomfort related to certain things which are good for you in the mid-term, but tedious in the moment. Examples are going running, waking up early, exercising or learning a new language. Another German periphrasis of that kind would be "über seinen eigenen Schatten springen", which is, according to Linguee, "a leopard cannot change its spots". I hope that is helpful.
One wonderful depiction of this expression is done by the German Comic author Flix, here.
(I am sorry if I should have put this question in the German forum, but I think it would not have been appropriate there, either.)
Edit: Ideally, the imagery of an external creature or foe that has to be surpassed, or a friend that has to be supported, should remain part of the expression. But I am guessing I ask too much here. ;)