I'm so sorry that this happened to you. It sounds to me like you did the "deer in the headlights" thing and were somewhat paralyzed by fear. In no way am I excusing the behavior of others, but you need to be able to project confidence and strength and be prepared to defend yourself, since abusers/rapists often smell fear and like to move in for the kill. One thing you may want to do is to work on cultivating some good response tactics, in case you have another unpleasant encounter with this guy or others.

A book you may find interesting is The Gift Of Fear by Gavin DeBecker.

I hope you feel better soon.