I'm starting to remember and feel shame.

I was the age of either 12 or 13 when I first started using chat rooms online. I met people, some of whom I dated, some of whom I still have as "friends" on Facebook, some of whom became stalkers and threatened my life at times. One particular person that I recall meeting, was named Brittney, she was supposedly my age... or maybe a little older, honestly my memory lacks when it comes to the details. I would text them during school, I was 13 at this time and had just realized that I was not "straight" leading up to this realization I was dating a boy in my class, we'll call him J, we began dating my freshman year of HS because a friend of mine thought he was cute and that I should go for it... little did she or I know that he would eventually want nothing but sexting, nude pictures, and to try to get me to have sex with him. Towards the end of our relationship, one of our many "ends", he wanted me to try masturbating on the phone with him.... I had never masturbated before and barely knew what it was. He instructed me on what to do and at some point, for a reason I can't remember, he decided to send me some lesbian porn. This struck a cord and suddenly life made sense
 
Back to Brittney, after J and our very sex oriented relationship I felt a crushing need for attention, affection, and now believed sex was the way to get those things. Even if I didn't fully give myself sexually. I began finding this attention online, sometimes I would give my phone number and begin talking to certain people anytime I could. Brittney, though I can't remember "her" age, where she supposedly lived, or where I met "her", I do remember some disturbing facts that stick with me to this day. I would ask Brittney how she was, wanting an actual answer and she would respond "horny" I would tell her that I wanted to actually talk and she would get mad, I would give in and sext her, often during class, she really liked pretending we were at school together, sneaking off somewhere. Brittney would have me send her pictures of myself, getting mad if they weren't exactly the right angle, they would make me redo the picture multiple times until I got it right. 
 
I don't remember how this subject was introduced or how I first reacted, but Brittney began asking for pictures or videos of my urine, my period blood, and at times... my feces. This is what disturbs me still to this day. When I would refuse or say that I just wanted to talk, Britney would be angry, say they would post all my pictures on the internet, they would find me and kill me, etc. I was scared and would do what they wanted. After an unknown amount of time I finally just stopped responding to Brittney's texts, I pretended it wasn't happening and that if something bad happened as a result of not giving in, at least I wasn't doing bad things anymore. After a few weeks I missed the attention and in a moment of weakness, I texted Brittney, saying hello and that I missed them. They responded with a "who is this?" I felt sad but scared and relieved. I deleted Brittney's number and prayed that this would never come back to bite me.
 
Upon remembering these details of my past, I remember asking for pictures in return and would rarely get them, if I did get than that were strictly model shots, nothing gross, all of which looked taken by someone else. They were of a skinny, young, brunette girl. I fear that Brittney wasn't really a girl but rather a pervy adult, sending me pictures of other victims. I fear that I allowed myself to be a victim of an online pedofile. 
 
What bothers me the most about this is that the disgusting sexual fetishes have followed me into adulthood. I can't say too much about that now, perhaps another time.... admitting this is hard enough.