Sounds like he's projecting quite a bit on you. How did he interact with his own mother? I would say that he is in that world were he's looking at you as his authority figure, i.e., mother.
They do not have a filter and he is looking at your daughter as his best friend because he is at the same age that she is mentally. Such a shame.
Sorry to read about your back, but he's really out to lunch if he thinks you are going to the doctor and get a note for your back, i.e., he's not your employer and that is something an employer would ask for.
Stay the course and I do hope your back is better today.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.