How Do I Stop This Pain In My Heart?

I just need some words of encouragement or something. something to motivate me to keep moving forward and move on. and stop all this pain in my heart. i am in love with an ex of mine. and he never treated me good. it was a very on again off again relationship. and i just can never get over him. i'm not sure if its that i'm in love with him, or im in love with the idea of him, and i'm stuck in the past. he was my high school sweet heart. its a bad relationship. we are not compatible. we always had amazing physical chemistry. i don't know. he has a new girl friend now, and it hurts so bad, think about him all the time. any advice for finally breaking free of this dysfunctional love and finally moving on with my life. how do i get over the hurt and the pain in my heart. i just want the pain to go away. i'm sick of this pattern. thanks.