I Don't Understand.....WHY IS THIS HAPPENING????

Why is it when lives change so drastically, one involuntarily dwells on the past, the "what-if's" and possibilities of the direction their life could have gone?
For some stupid reason I can't help but sit here and wonder what my life would have been like had I stayed with Bill. I try to push any and all thoughts of him to the farthest reaches of my mind, but somehow they push and shove their way to the foremost part of it. Why is it my memories of the times I spent with him constantly come back to haunt me? What did I ever do to deserve this??
I don't want to think about him, don't want to remember him, don't want to have anything to do with him, but these repressed thoughts won't fuckin leave me alone. How the hell can I get rid of them?
I love the man I'm now with more than anything in the world. He makes me happier than I ever thought I could be. I want to talk to him about what's going on, but I don't think he'd understand..
So why the hell do I continue to think about and remember my ex? Why is it that I can't seem to get him out of my head? Is it because we've known each other for so long?
I constantly try to rationalize why I think about him and our past history. I'm sick of all of this. And now, for some dumb reason, I just read his blog and the words he mentioned about me, even though he wrote them months ago, still manage to hit me hard. I don't understand why. I wish I did, but I don't.
CAN SOMEONE PLEASE TELL ME WHY THE FUCK HE STILL MANAGES TO TORTURE ME?????????? AND HOW THE HELL I CAN STOP IT?????????????
My sister and my ex's sister are best friends, and knowing that they hang out doesn't help. Every time I hear Amy's name it reminds me of her brother, and the shit starts all over again.
SHIT.
I could really use a stiff drink right now.....
*rolls eyes*
If only I wasn't pregnant.........