Ex problem

Okay, so I know that I am way younger then a lot of people on here, but I could really use some advice. So I'm a freshman and my mom let me date this year, I didn't want to. I didn't want to because 1, I have really high standards and no one at my school meets them and 2,  I just wasn't ready. After a while, almost the whole school year, I found out that a lot of guys liked me.  Within all these guys was one (not putting names) who literally stopped at nothing to get my attention. He bought me flowers, chocolate, and teddy bears. One day, he took me behind the school and asked me out. I didn't like him but I said yes so I wouldn't hurt his feelings. He rushed things and tried to kiss me on the second day, he was my first boyfriend but I know that your not supposed to go that fast if you aren't ready. He then tried to get me to tell him everything last little thing in my life. The list goes on, but let's just say, the relationship was only six days and I broke up with him, he then begged me to stay with him. 
Now he is spreading rumors about me, turning my friends against me, getting his friends on me and calling me a slut and a bitch. What really bothered me was he said that he broke up with me because he found out what a "horrible person" I was and that I begged him to stay with me. This offends me because I'm an independent woman, as I've said before, and he knows nothing about me. I really want to handle this professionally, since we are in a theatre show together, I don't want to yell at him or spread rumors, I just want this to stop, but I don't know what to do. I could really use some help.