Swings and roundabouts...

My writing seems to flow in cycles: I've faltered in my WW2 story so I have gone back to another story, trying to get it ready for someone else (probably my mother!) I know they seem good at the original time of writing and I still like them but an element of doubt always creeps in... are they good enough? And, of course, it's so difficult to change them, especially if drastic change is needed!