he makes me confusion

yes I know I said confusion, it's the perpetual state I seem to be in around him. we've known each other for 2 years , I didn't really see him throughout high-school until lower sixth we were in the same class. I liked him then but then his ex who I didn't know either befriended me just so she could keep an eye on the girl he was constantly hanging around (me) she told he did her wrong but that she still loved him , obviously not wanting to ruin their chance to fix their relationship I backed off. deleted his number cried myself to sleep the works really. He however did not take this lying down so he stopped me after class asked why I was avoiding him, I couldn't look him in the face at first but then I got angry and told him what was happening, he told me he wasn't with her anymore and that she sabotages all his relationships.She of course said she went to his house a d they had sex. He said he did cause she offered and threw herself at him I want to believe that they are over and that they are not the couple that's meant to work things out , but her face looked sincere when she told me she loved him, and the sad part is I love him too , and he kissed me once it got heated and I ran away like a stupid child, (not a Virgin but I only did it once hand I vowed it'd never be meaningless again) I really dont want sex to be the only memorabilia of our time together, only for him to not return my feelings this is my last year of high school I don't know what's gonna happen I want to forget him because he makes me feel more than I want to and this girl won't let him go and she had him first so I have no right to him,. i know I wrote a book trying explain me ,but it literally feels like I'm dying , I'm sick of avoiding him but I really dont want try when he might get with me then leave . she's really pretty and has enough curves to outshine mine and I cannot see how he'd not choose her if he had to choose.