She is confusing me, I am desperate and really hurt right now.

I've been with this girl for a year. We talked about getting married and being with each other forever, I honestly thought she was the one. We started college and she started acting different to a point that I couldn't help it anymore. She said she started to lose feelings for me and that she wasn't attracted to me anymore and that she wanted to be with me. Yesterday she kept calling me more than 17 times and messaged me this:

please say something

please

i would really like to talk to you

please

ive called your phone 17 times today ill stop bothing you

bothering***

alex please call me

im wrong and stupid and you can be mad at me but i have to be with ypu

can you just tell me to **** off or something if you wont respond to me

i cant focus and i cant do anything i was sitting in my room in the dark all day i literally cant function and its all my fault but i need you and i was wrong to think i could be independent im sorry just say something

please

your still on my mind 24/7 and my profile picture is us

alex please i will do anything you want anythinng in the whole world

i know you want to say something to me, please say whatever, i cant not be with you i need to talk to you i need to share my life with you and experience it with you

alex please

you dont have to move on im not moving

so you log off so i wont message you but now your on

i dont get it

please respond to me

i would really appreciaate it

give me something so i can stop bothering you or keep bothering you

im waiting for you to say anything please say something

i know you can do better than me and ignoring me i really think it means you dont want me to talk to you so i wont sorry

then she went single and change her profile picture on facebook so i decided to call her back but she told me that the night before she hooked up with somebody because she wanted to see what it'd be like hooking up with somebody else and said it was okay. I was so hurt so I decided to not talk to her ever again. Today she didn't talk to me or anything so didn't I. it hurts so much because I thought she was the one and she just says she doesnt know how she feels about me anymore. What do i do? Do i talk to her or not.