Hanging On Versus Letting Go

For the last three weeks, my family has been debating "hanging on" versus "letting go." Here's the situation:
During our spring vacation, I flipped out of a river raft in a Class IV rapid. I held on to the thin safety cord attached to the raft with a grasp so intense that my pinkie finger was numb for the next ten days. And I injured my shoulder. It all happened so fast; I didn't know whether I'd smashed my shoulder against a rock, or tore it up by hanging on. Thus, our family debate.
I held...