Shining, You are doing great. Allow your man/child to figure out where he's going to store his piano. He could always rent a storage facility and put it in there or ask one of his friends to store it for him. I agree, he's had plenty of time to figure it out. He's still looking to you to fix things for him. Time for him to step up to the plate and take care of his own stuff. You've got a lot on your plate.
Time to let him figure this one out.
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.
