I'm bisexual, nobody knows and he's threatening to tell!

Dear Diana,
I am 19 years old and bisexual. Two years ago, I met a guy online and he claimed to be 24 though he looked 27. We chatted for a few months and he proved to be a really nice friend. I was just getting out of a broken relationship and he proved to be a shoulder to cry on. We decided to meet the first time, we spoke and later, he molested me. I later gave in and we grow very close and met many times. He gifted me goodies which I accepted. Later on, through common friends, I found out that I wasn't his only target. He had other playmates at around the same age as I was. I started moving away from him and began patching up with my ex. He realised that I knew about his game and he started using all the information he gathered about me against me. Heu00a0 called up my ex, contacted all my friends through Orkut and started telling on me. My parents don't know about my sexual orientation. He threatened to tell my dadand would send threatening messages at odd hours. He stopped for a while but has begun it again. I cannot tell my parents. I met him at age 15 and he still harasses me mentally. I have no other option but to continue to let him torture me.