You don't have to be happy to produce scholarly writing, and producing scholarly writing doesn't produce happiness either. I'm living proof of that. Feelings of dissatisfaction often come at times of professional success. I noticed some disturbing symptoms in myself recently so I made a list of things to work on immediately:
caffeine / alcohol
Regulating time spent on internet (randomly) and coffee use; having one beer or glass of wine with dinner (or none) instead of two; exercising daily and beginning short sessions of meditation; making sure I meet with friends more often and eat better food. All of these things are mostly within my control. I have that list on a piece of paper at my desk to remind myself.
These factors alone won't make me happy, but they might bolster the happiness base, which in turn contributes to the management of everyday life and the scholarly base. Severe unhappiness can make me unable to work or to enjoy the fruits of my work.
*The concept of the happiness base is from the poet Kenneth Koch, who attributes it to a friend of his whose name escapes me at the moment.