My sd card lost everything

A few minutes ago I was trying to link 2 consoles online, but when I disconnected it the games in it were gone. I reset my device to see I could only access the internal card not the external. So I turned it off put it in a laptop and it says the sd card needs formatted before it can be used. I have a lot of game data on it that I would really hate to lose, so if anyone knows how to restore it. I would like to know. By the way, the other console still has everything. Mine was the host, and the other was the one connecting.