Stressed and overwhelmed

I was recentl my sexually assaulted by a stranger outside my car when leaving a friends house. A man pinned me against my car, ripped my shirt up and left extremely dark bruises all over my breaths and bruises between my legs from pinching trying to force my legs apart. I fought him off and he left. I didn't report it because I already knew there wasn't going to be enough (if any) evidence/DNA to catch the guy so I didn't want to put myself through even more stress. I figured that after the bruises all heal it will just be over, but  I haven't gotten that far in the healing process to know if that will be the case. My question to everyone is, did I make the wrong decision by not reporting the situation?