Is this cyber-bullying or cyber-stalking?

Okay there is a girl (lets call her mel). she is friends with my friend (and lets call her laura). Well in August I started liking (and him Brad.) and He was going to ask me to HC! I was soo excited! but my friend Laura liked him too but i found out in september.. and when she was talking about how Mel started liking Brad alot she was mad at me for being with him alot lately... So Brad asks me out after HC and of course i say yes! :D but anyways Mel gets oddly jealous and writes a status saying "oh he is amazing and well she is okay.. I will tell them they are cute but she is not for him!" and her friend Jen wrote to me that yeah it was about me and Brad. So I told her that was really mean and i want to be friend... so we started texitng... I stopped after a while cause i was really busy. Well brad and I broke up and she is like SERIOUSLY?! U guys broke up! why??? and I was like okay srsly I hate that question back off! and she was soooo pissed. I was mad cause everyone asks. and she thought i hated her and i didnt.she started to text me why do u hate me? I explained it was innapropriate for her status to be like that and It was not very nice but i didnt hate her... she kept pushing me five times and she just kept asking... and we made a truce EACH TIME... One day she was like wow i cant believe u hate me... I got soo pissed! I could not handle her pestering me anymore!!! I told her im sick of her asking and all she was was jealous! and she said she was!! and she was like wow bye hater. And i told her bye *****. bad choice of words from me :P she says a week later im really sorry. i ask her for what? she said for erm making u hate me? I didnt answer.. last night after being with my friends i get a text from her number saying "we hate u." another one saying "this is liz right?" "liz helgahans?" I got so pissed! I told my mom and she said we can go to the police... what should i do? PLEASE HELP ME! she is the worst thing... Ive never had such rage... thank you in advance..