My ex simply wont leave me alone.?

After 14 months of going out he finally had it with me and said it was over, he didn't feel the same way anymore, we always kept fighting and that things weren't going to change. SO a few weeks later he messages me on myspace which a stupid comment on how I am supposably "changing" into something I said I'd never be mind you this is just because I dyed my hair black and blonde. He just had to tell me because he found it funny. Then a few days ago he comes up with this whole idea that I was cheating on him while we were going out. Never in my life would have I ever done that, and if it wasn't for him I think I'd still be going out with him. Except now Me and a friend of his has been hanging out alot lately, and that is whom he is accusing me of cheating with. He's nuts he sent me rude emails as to how I am a piece of **** and I deserve to die alone, ect. He's pyschotic, I am not kidding you. He says hes bringing it up now because I disrespected him, really? Why do you think hes brining it up it shouldn't even matter he is the one who broke up with me I just want him to leave me alone so I can continue on with my life, it sucks. We are going to have a conversation I guess too, but he keeps flaking out he can talk all this **** online yet he can't do it in person? why is this? I really am confused.