Is this harassment and what can I do to stop it.

Hello everyone, I am a 16 year old boy and about a month and a half ago was dating a 17 year old girl, who I will refer to as Rebecca. We dated for about 2 weeks until our relationship crashed to an end when she cheated on me by having oral sex performed on her by another guy. Rebecca had told me what had happened herself and I broke up with her at that time, wanting to just separate and forget she was ever in my life. Because of what happened she has been begging to date me again for the past month. It started as her crying saying she was sorry and that she "never actually cheated on me, she just felt like she did". But what started as simple sadness, turned into what I believe to be harassment. In our very short relationship, we had both performed oral sex to each other and she tried to have sex with me, but because of how much pressure she put into sex, I couldn't get aroused so we never did have sex. In an attempt to reconnect with me, she tells all her friends, my friends, and all these people in our school how I am and a "softie" and "the worst a sex", even though we never did have sex. She then decided to step it up a notch by manipulating what happened. She tells people how it was my fault and that I abused her, things I never have done. She texts me day in and day out threatening to do things such as, "Tell my parents all the horrible things I have done to her" and "ruin my life". She tells me how she has done it to many of her ex-boyfriends and how I will be next. I do my best to try to mediate and be nice to her, but even thinking about her makes me shake. It's like I don't know where to turn. Anywhere I go I feel i'm haunted by the decisions of that 2 week relationship. I just want to forgive and forget but she won't listen to me. Day in and day out she continues to what I see as bullying and harassing me. All I want is to move on so I can stop being worried and be happy again. Sorry if the story is a bit jumbled and rushed but there is a lot of emotion in me and I don't know what to do. Thanks in advance to anyone who tries to post and help and if there is any vital information that I left out, feel free to ask. Again thank you to the people on this forum, if there is ever a time I needed advice and comfort it would be now. Thank you for reading.

This girl is a manipulator and a bully, and you need her out of your life. Have you confided in any adults about what has been happening? She's been spreading things about you, now you need to tell someone who can put a stop to her behaviour. She sounds like someone who is doing this to all guys she dates.