Unfortunately, I have to agree with mena and say, this is a learning lesson that men can certainly be hurtful sometimes. Women certainly can ge attached to men after sex emotionally and men tend to think of it more as an activity and move on quickly.
I hope that you will cry, be sad and remember that next time.....it may be worth waiting to have sex. I am sorry that this happened to you, but your certainly not the first nor the last. Good luck.