Your rage took you away from the situation, which is what you needed right now. Dark and malevolent thoughts bubbled up inside you and you imagined more and more creative torments all of which were directed at your unnamed attacker.
You became lost in the darkness, completely dissociated. You didn't notice as his moans became mixed screams of pain and horror, or when his rhythmic thrusting became frantic yanks to free himself from your backside. The darkness accepted you as you were, it didn't judge you for not being kind nor mock you for not being able to protect yourself, nay, it simply enveloped you in the emptiness and let you rest there in your moments of need.
You did notice as he hit you with a kidney shot, white-hot pain shot through your dark reprieve and your anger grew. He screamed in sudden agony and his next blow was more an annoyance than an injury. Roused from your stupor, the man yanked away from you and went flying backwards, slipped on public restroom wetness, and hit his head on the urinal he slid into a slouching position against the wall having knocked himself out...
In your right mind, you would have immediately run, but you were drunk on the rage and vengeance you just indulged in, and still filled with urine, you stepped up to him and pissed all over his vulnerable, unconscious body.
It took almost a minute for your bladder to empty and you made sure to cover his face getting behind his stupid sunglasses, aim for his barely open mouth, and coat his whole body. Even unconscious the man was someone you would know not to mess with. Though looking sickly pale he could easily play Captain America if he wasn't too busy accosting people in bathrooms.
The rage welled up again and you thought about ending him there, a few good stomps with your shoe, a pen in the eye, or anything sharp to his throat could do it. You could stop the bad guy! A sneer crossed your face. Just a few good kicks into the urinal and he wouldn't hurt anyone ever again. You took a step forward before coming back to your senses, you didn't want to be a murderer!
Your body feels strangely sluggish and unwieldy as you return to your car. You return to the road as quickly as possible looking in your rearview mirror, irrationally fearing him chasing after you. You are in a car on a highway after all...
After a few minutes of deliberation you had made it to your exit, you pulled into a well-lit gas station, locking the doors, and with trembling hands, you called the police.
After dodging questions of who you were and where you are, you shakily said, "I need you to know there is a rapist, knocked out, in the men's room of the Route 73 rest stop."
"Sir! Were you attacked?"
"Could you repeat what I said back to me please?" Your voice cracking and tears streaming hotly down your face.
The representative read back what you had told them, "Thank you, he may need an ambulance." and you ended the call.
The sudden silence was too much and you needed to fill it. You screamed, hit the steering wheel, and sobbed uncontrollably pouring your feelings out into the darkness for whatever time it took to subside. Pride at showing that piece of shit mercy, shame at being defenseless, anger, rage, despair, hope that he never does this again, and joy that you weren't stabbed, beaten or murdered. All sorts of emotions flooded you and you violently expelled them into the darkness unable to hold them any longer.
Finally, in the emptiness, peace washed over you and in your head, these words formed, "You have given us your rage, and we tested you. You passed and you return to us with more offerings. We are pleased and you will be rewarded."
Your eyes pop open and you feel strangely empty emotionally, strangely full physically, and tired. You shift the car into gear and see the attendant eyeing your car suspiciously before you drive off and you laugh at the situation as you go home.
Making it home safely you let yourself in and quietly go to your room, collapsing on the bed fully clothed, you sleep a deep dreamless sleep.