First of all you need to get over the idea of being with him forever. You are going to have many relationships in your future. Get past this "one and only" idea. I know its not what you want to hear, I thought I'd marry my high school gf.
Second. Leave him alone, stop texting him stop calling, if you want him back thats the only way to do it.
Besides, if he doesnt want to be with you, than you will never be in a happy relationship with him. Sometimes you can guilt people into sticking around for a while, it only breeds resentment. If somebody's not happy in a relationship it wont work and its not good for either party. As you get older you'll realize this. Sure its sad, sure you'll be miserable for a while, thats life and its unavoidable. Eventually you'll get to look back and have bittersweet memories of breakups. They'll make you who you are, so dont stress too much about losing this one. Cry it out and move on.
Second. Leave him alone, stop texting him stop calling, if you want him back thats the only way to do it.
Besides, if he doesnt want to be with you, than you will never be in a happy relationship with him. Sometimes you can guilt people into sticking around for a while, it only breeds resentment. If somebody's not happy in a relationship it wont work and its not good for either party. As you get older you'll realize this. Sure its sad, sure you'll be miserable for a while, thats life and its unavoidable. Eventually you'll get to look back and have bittersweet memories of breakups. They'll make you who you are, so dont stress too much about losing this one. Cry it out and move on.