Using the model coaching someone with separation anxiety

I was trying to coach a young patient of mine (pre-teen) regarding his anxiety about sleeping alone in his bed. he has been increasingly scared lately and going to sleep with his parents (he is afraid someone is going to break in his house and murder him- his words). He goes to mom and dad bed to avoid feeling scared and working himself into a panic (where eventually gets sick and throws up). I tried applying the model but seem to get stuck in the A and R lines to show that the R reflects the T.

C: Sleeping alone in bed
T: Someone will come murder me
F: Scared
A: Goes to sleep with mom and dad, and/or gets sick and throws up
R: ?? Not sleeping alone?

I feel as though he is changing the C to make himself feel better, rather than changing the T. New Model is:
C: sleeping with parents
T: no one can hurt me here
F: safe, secure
A: falls asleep easily ?
R: ? sleeps with parents ??

Help! how can i be working this model differently? I was able to work and intentional model with him think positive thoughts to make him feel safe in his bed

C: Sleeping alone in my bed
T: My house is safe, i am not really alone, my family is nearby, there are locks on the doors, etc.
F: safe
A: falls asleep without help of parents or getting sick
R: can be alone because it is safe??

his family is teaching him to try to think of happy places he’s been or other happy occasions to focus on when going to bed to keep the intrusive thoughts out.. is this helpful too? i see it as a distraction technique, but it can work….any thoughts or guidance would be appreciated!!