You can dangle yourself the carrot that it's just until you get out of the first hole: "Once we're live, it'll all calm down and I'll be able to relax".
But that's rarely how it goes. The reality is that you're never going to be done. There's always more work. New initiatives, new customers, new competition, new technology, new ideas.
One pattern to help yourself fight the mad dash for the mirage of being done is to think of a good day's work. Look at the progress of the day towards the end and ask yourself: "Have I done a good day's work?"
Entrepreneurship a marathon, not a sprint. Set yourself targets, beat them, then allow yourself to feel good and relax.