Barbara Pugh suggests we use writing to keep sane. Although she has “never tried to get published so I've never written specifically with that aim in mind…” she still has suggestions for fellow writers.
Writing can be very useful for keeping your mental equilibrium! Hate your boss? Write about it, and let your imagination go bonkers. Want him boiled head first in a vat of fudge sauce by mutant zombie law students? No problem. Mother-in-law revealed to have been working for years as a cold heartless russian spy/assassin? Yep we can do that.
Hate your boyfriend and want..well keep that one to yourself, maybe.
Sometimes just using your writing to enjoy and sustain yourself is a goal in itself!