If I'm getting beat on a fast break I usually try to keep moving but alter the direction to get an angle through the play. If that is not possible, I stop just long enough to see that play then continue down.
In my opinion, if you are getting beat continously you are either out of shape or you run in the same place for too long
There have been times (twice in boys games) where in the first quarter and a half I was getting beat consistently...both teams just had a lot of speed. I starting setting up deeper when at trail. If you do that, remember to take two quick steps toward the foul spot when you blow your whistle...that way when everyone locates the person in the funny looking shirt that just blew his whistle they see you in better position.
That's just what I do...but then I am not the one evaluating you or assigning you games. Did you ask him what you could do as an alternative?