I might need to take Mazedude's excellent advice. I especially relate because I also have a family and a full-time job, so my only time to work on music is at night (usually after 8-9 PM) and pockets of time on the weekends. So, I've been doing the opposite - staying up late. And it works okay, because I am generally NOT an early riser. However, I think it could be worth a shot to see if I feel more energized and productive by getting up earlier as opposed to staying up until after midnight.
The whole idea of finishing something I've started as opposed to cycling through different projects without completing anything is something I've been continuously working on, and something I really was never any good at until well into adulthood. Interestingly enough (and this is just how it worked out for me), taking a break from music for a few years and raising my son has actually re-energized me, so I'm a much more disciplined and focused person than I ever was before. So while I have less time than I used to for noodling around on instruments or working on projects, I'm much more efficient and productive with the time I do have. I finally figured out that the joy of finishing a project helps carry me through the day-to-day challenges of actually keeping my commitments and doing the not-so-fun stuff sometimes. It's a wonderful feeling!