Oh dear, take a deep breath. It did turn out beautifully. I wish your husband success in his surgery. You have far more to deal with right now than how a quilt is finished, and you realize that.
I have not heard of doubling thread for quilting, but I don't do hand quilting. For this project machine quilting would probably be better, but... you've done enough for the cause. Just be with your family and best of luck to all of you.