I've not gone hru a loss of a dog when I've had two yet, but I can speak to the fear/floundering issue. My Brin is fairly skittish and looks to my Zola for leadership. When Zola is not there or not willing, Brin looks to me. For me, being a strong leader for her is showing that no matter what scary things are going on (fireworks, thunderstorm, etc), everything is ok. It's not that I won't give her a cuddle as need be, or hold her when shes trembling, but I will insist after a whle that we walk about the house together or even just stay in the same room and I will talk to her (in a normal voice, about my days, the news, whatever).
This approach seems to work with Brin now although I suspect that if lose Zola first, Brin will need another grey in the house.