Maybe consider this Rob... I only feel guilty about not working on models on weekends. I have all the time in the world, time even reserved for just that. Yet Sunday night nothing got done.
I've concluded it's because modeling fits into weeknights after supper much better than on weekends when everything else is going on, even if it's sleeping, goofing off and vacationing from the weekday obligations, because that's what I need to recoup from the previous week's day job. And as mentioned before, the model will always be there. If they become an obligation, you don't feel (mentally?) rested.
Thusly, things more recreational get your attention. Guilt not my friend.