help!

i'm 25 and my story is embarrassing to tell and i feel like i can't talk to my family about it. I found out my fiance of 5 years was cheating on me and I freaked out and kindof went off the deep end. I was so depressed and felt lost and alone. I met up with a friend from high school who i knew had some problems with drugs i figured i could get away from it all and spend a weekend doing that and my pain would go away atleast for a few days. Long story short I was told if I did crack I'd forget all about it. I know it sounds stupid but at the time I was so desperate to just run away from my pain. anyways I decided to try it. Two days later I woke up not knowing where I was or who I was with. I woke up naked with some crackhead and totally freaked out. Later I had found out that we had used protection but the condom broke and I know that I am a very fertile person. That was a few weeks ago i went to the doctors yesturday and got tested for everything and she insisted that I get a pregnancy test also. It's April 30th and my last period was march 12th and she things that I am pregnant. What scares me even more is I don't know who this person was and my so called friend won't return any of my calls. It will be a couple days before my pregnancy test comes back from the lab but I just know that I am. I didn't mean to do this and I don't even remember doing it. I just don't know where to turn from here