I was taught really young that distance running actually becomes a little more difficult when you take a break to walk a ways. The idea being that every time you walk to give yourself a rest, you have to exert more effort to regain the pace you had previously. If you can push yourself through the difficult spots in your run, and instead just moderate your pace, you will have a more successful experience running.
I believe the same is true about writing. It becomes more difficult when you stop doing it. However, as a busy wife and mother and with a FT job, finding time to right often comes in fragmented pockets of time - 15 minutes here, half and hour there. How does one keep enough flow of writing to make the most of those short and sporadic writing opportunities?
One trick I found that really works was shared with me by author Stephanie Humphreys. She suggested I keep a binder or notebook for each WIP with various sections for character notes/research/setting/plot/etc. However, her suggestion was that one of the sections be strictly for writing down the last thoughts I have about my work before walking away.
So if I'm writing a paragraph in chapter 22 from my hero's POV, before I save and close my file, I need to remind myself what I want to happen next. It seems like a simple thing, but I find it very effective. There is so much in my life to occupy my thoughts and wishes and concerns, it is often difficult to remember such a simple idea in my story as what I thought should happen next.
Even if I change my mind in the interim, at least I knew where the story was headed the last time I sat down to write it.