I have no idea how old you are but is it possible you are pre-menopausal? I am 47 and started a few years ago with the erratic periods, foggy thinking, forgetfulness, horrible sleep patterns - sometimes I sleep all night, sometimes I'm up every 2 hours. Just a thought.....
I, too, have a son that interrupts nearly every good thought or good book that I start. He is homeschooled so that's part of the deal, but it makes me feel constantly off center, unorganized and I forget a lot because of it.