I am emotionally wrecked , how do I move on PLEASE READ!!!?

Okay. I have a boyfriend,but I'm still inlove with my ex... My ex & I had a son Last month that I had to give up because I'm still in 11th grade & I'm not financially stabeled for a child. My ex is in the military. He isn't near by. He's a thousand miles away. He was my first in making love . I miss him & there is honestly a piece of me that's telling me your never going to stop loving him,it's almost like torture. Because it's been since April of 2010 that I've been dealing with this heartache. My heart hurts when I hear from him.... Big mistake, he came home for christmas & I saw him 5 times. He spent the night at my home & we made love. Sadly, I found out two days ago he told his buddy's and his buddy's happen to be my current boyfriends buddys. My boyfriend was upset because before we got together (about 2 weeks ago) I told him I haven't had in almost a year now, but he found out I had with the one I was inlove with & thathurt him. I feel bad,but I can't change my past. Me & my ex got in a huge argument and now we don't even have a friendly relationship,it sucks..... I've been crying about this all day. I miss him, but I think it's time to move on... I feel sad,betrayed, & used in so many ways.. How do I move on for good...? I'm 17 btw. 18 in April.