The whole accident with the ball... sounds horrible! Kids and balls can be a really dangerous combination. I have a son, so I know what I am talking about!!!
I sometimes listen to a guided meditation app that I downloaded on my phone. Take it with me to bed and play it to help me get relax and my mind to stop circling around painful thoughts and memories. Use my headphones, and sometimes I plug this little loudspeaker I have into the phone and listen to it that way. ( one of many blessings of being single, can listen to guided meditation without waking anyone up). I dont have
the problem of waking up once I am asleep, but maybe you could try to just turn on the meditation again, and see if that will bring some peaceful sleep? I used to have a frightening nightmare that came back night after night some years ago, and I honestly didnt know how to deal with that. But I was stuck in a situation that was really bad for me. When I managed to change my situation, the nightmare started to go away. It was really hard, and I remember I feared going to sleep because I was scared of the nightmare...