I don't have a citation for this, but I read something recently about a study where people who had been introduced to the concept of decision-making fatigue experienced it, while people who weren't aware of it didn't.
The mind is a wacky thing, I think we know a lot less about it than we believe. One idea I like which seems to have some real world support is that your mental models make all the difference -- if you believe that something's hard and unpleasant, your belief becomes a self-fulfilling prophecy and you'll experience distress when you do it. If you're able to somehow reshape your beliefs, that distress may diminish. Cognitive behavioral therapy is based on this model and has a strong clinical track record.
The mind is a wacky thing, I think we know a lot less about it than we believe. One idea I like which seems to have some real world support is that your mental models make all the difference -- if you believe that something's hard and unpleasant, your belief becomes a self-fulfilling prophecy and you'll experience distress when you do it. If you're able to somehow reshape your beliefs, that distress may diminish. Cognitive behavioral therapy is based on this model and has a strong clinical track record.