" What you need to do is stop feeling responsible for things you have no power over."

I believe that's a wrong mentality, hence that's actually how my Ph.D. advisior does to me and its pretty painful on my end. My advisor does exactly your advice as he just stop caring about me and focus on his projects success. Probably he thinks that "I have no power over my student's success or process so I just stop being responsible about it to be not stress out.".

I think you have power over to help others and communicate the way you feel about your situation right away.