Harry’s Patronus

Harry lies there in the brush watching as the death eaters swarm toward him. Not toward his current self, but toward the past version of himself.
He lies there, waiting for what has already happened to unfold. Waiting for his savior to come and cast a magnificent silver patronus, dispersing the death eaters and their darkness. He waits anxiously with bated breath. He knows it will happen because he’s already seen it. He waits for his savior - but they never show. At the very last second, right before all is lost, he jumps up, casts his own patronus, and saves himself.

There was nobody to wait for. 

He was his own savior all along.