I stabbed a rapist a lot

I (19f) was drugged out of my mind in my car and my friend (26m) told me he wanted to try some pills and he put them in my sprite to see how it would affect me. I didnt even realize he was raping me until I looked down. I can't stop thinking about it and its killing me. why do I feel bad? I just kept stabbing him with my car keys. he said he never wants to talk to me again and how it "wasn't that serious" but I just felt so violated. did he get me pregnant? Will I have a STD?