I think your sister has a great idea. Try talking to him in a different manner. Make suggestions as to how to arrange things in the home, i.e., bookcase. This will allow him to make some decisions (and you will have gotten what you wanted in a roundabout way).

Hang in there!

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.