I'm so sorry this is such a shocking trigger for you Chalkdust. Often those out of left field ones hit us hardest. You've recognized and connected why this is triggering which is more than many can do when thrown for a loop. Good job on that. Small comfort but we have to see the positives within the scary times to keep getting through.
I am glad that you posted here. Please do anytime you want to or need to.
Wishing you peaceful rest after your step-brother leaves.