Hello, Well you said "someone you loved before" that means " you don't love him anymore" , you know what the real problem is , you are just stuck there in old memories with someone who probably wouldn't be thinking about you at all and minding his own business, while you are the one who is hurting yourself by not breaking free of that memory .And if he doesn't love you as you say ,why do you insist on directing your emotions towards someone who doesn't care ,that is really pathetic , i am sorry. What you can do is altering your own behavior and concentrate on something else to fill the emotional gap in your life, try to know someone else as Mike says . The world is full of other guys ,just look around:)

Let time helps you......and keep busy all the time you can.

If "You" Consider that the feeling of this person toward you is main cause to love him/her,you'll find forgetting him/her a lot more easier .

Right now, you may feel that he is the only person for your heart. With that you are only caging yourself. Good memories are really hard to forget, and to start a new life is difficult to initiate. All you need is a courage, believe that the world out there is a big ocean, full of hopes and dreams. Goodluck!

Time heals all wounds no matter how deep they are. ( it sounds like a stupid crap but really works ) Just try not to think about him, and cheer yourself up by hanging out with friends or watching comical movies, serials. Get rid of all the materials that remind you of him and stop listening Love songs :) That's all. Good Luck !