Can't know if this is of any use but... I was widowed raising 3 on my own and had to explain it somehow. I didn't understand it myself yet... but by the time mine were 10 they understood that 'mom's turning into a werewolf and will be out when she turns back'. I didn't go into details of how hopeless and threatened I felt or what I was afraid of. I just stopped talking (sometimes in the middle of a word), went to my room and locked the door. They understood it wasn't about them, they had no control, I had no control and it would be over when it was over and not dwelt on afterward. Sometimes I melted into a heap of fear in front of them but handling it factually afterward seemed to take the steam out of things... Then get on with 'real' things.