Finding my way to the end

I've been working on a new book...Okay, that's a lie. I've been trying to work on a new book, but so far in the last month I've done, like, seven pages. It's frustrating as hell. I know where this story is supposed to go. I know where this plot is supposed to lead these characters. I can see it. I can feel the creativeness building inside me every time I think about it. I'm excited to lead another couple on an (hopefully) unforgettable journey. The problem? It's all bogus.

I don't use outlines to write. I'm not organized like that, nor am I naive enough to believe that the story is going to turn out the way I want. I could write an outline right now about the plot I envision, and yet I know that as soon as fingers meet keyboard that outline is worthless. My characters are going to do whatever they feel like  and really I'm the one on the unforgettable journey. They are going to tell me the plot. My characters are the story tellers, I'm simply the writer.

But that doesn't mean that I don't imagine how I want it all to turn out. Right now, I can easily picture writing the middle. I can see it playing out behind my eyelids. Same with the ending. I can't get there though. I can't get passed the beginning. I'm stuck. Writer's block is an evil thing.

Do I write the  middle the way I want? Do I end the story without knowing how these two characters come together in the first place? Do I do it the way I want and just hope it all fits together nicely in the end? Or do I suffer it out, writing one sentence at a time only to go back and delete every single word over and over again?

Finding my way to the end depends on my characters. How do I find the end when there's no beginning?