I don't understand the conflict. My slave is my 24/7 slave and we've both got hectic lives. All being my slave means, is that my word is law. It doesn't mean anything else. If she is tired and all she wants and needs is a massage in the bath; she doesn't stop being my slave because I comply. I know I can use her any way I please at all times. But sometimes it isn't practical so I don't.
What I'm assuming you mean is that you don't like being a slave 24/7, which is completly different than can't. I guess there'd be a conflict if your Master was a total idiot who can't gauge the simplest emotional state of his slave. But I couldn't for the life of me understand why a woman would submit to such a man.