He Broke My Heart Again!

So I been seein this guy off and on for 2 yrs now....He's broken my heart soo many times but yet I still love him and always crawl back to him. He's used me in soo many ways But yet he is always on my mind. He broke up wit me because he said he didnt feel that way for me anymore. Then come to find out month later he was seein one of my good friends and they startin dating n slept with eachother. Ever since then hes been sleepin around wit all these girls it seems like every time I talk to him he has a new girl hes playin around with. Never can keep a steady gf. Why is it I always keep going back to him? Ive slept wit him alot of times he was my first one...Is that y I'm so in love wit him? I'm trying everything in my power to forget about him because I know in my heart hes always gonna keep usin me for sex, money etc and I can't let that happen anymore. I have not seen him in 6 months we talk on the phone but that's about it. How can I forget about him? He's on my mind 24/7.