Why does is still hurt??

I mean me and my bf were only together for 4 months! and i was really falling for him! but he was a wild guy and im a good girl and he said he felt bad being with someone who deserved better then him, so we broke up...i know thats just a line he was using, but we really did have something and i guess his wild side caught up to him again! but i was starting to get over him until i just now was reading our "myspace messages" from when we were together and all the heartache came back! i miss him so much, but now he's with some hoe! she really is no good for him! it hurts so bad! help me! I'm 20 and he's 26!