I know how you feel.
I keep thinking about that too. And it hurts so bad.
But then I think about all the times he lied. All the times he stole. All the times he said hurtful things. All the times he manipulated me. All the times he came home high. All the times he let me down and made me cry.
Being with him was just as painful as being without him.
At least this way you can move on, get better and heal. If you stayed he'd just break you heart over and over and continue to hurt you.
I know it hurts but this is for the best.
I am so sorry for your pain. It will get better.
I promise.
There is nothing left to hold onto with him.
You'll get through this. We both will. And we will come out on the other side of this happier and healthier people.
Edit
(And no you're not crazy for wanting that one last time I want it too I've actually considered paying my XABF's bail just to get that. But you know as well as I do it will just be so much more painful in the end and it won't be comforting to know you're in the arms of someone who has hurt you so much)