For the first-time novelist you've got to get up at 5:30 in the morning and write until 7 make breakfast and go to work. Or come home and work for an hour. Everybody has an hour in their day somewhere.
Your 40s are a major trough. About the age of 50 feelings of satisfaction begin to rebound and keep rising into your 50s 60s and 70s with health being a major factor.
