My experience after learning anything new (and major!) is that -- looking back from a perspective of far more practice, I'm appalled to remember all I didn't know. This training is to prepare you for what someday may be a life-and-death situation. You owe it to yourself and the people depending on you to be really, really good at this. "Borderline" won't cut it. Your assessment team may have done you a real favor. Only time will tell. Meanwhile -- consider that "more practice" at this point can only be a good thing. Life itself may eventually show you why. In fact, it probably will. Keep at it!