I understand that you want to break up... and from what little is written in your post, I can sort of see why.
Has it occured to you however that it isn't her that you are trying to leave? In your first post you mention how you are an introvert and that so is she. From the way you mention it, and the way you bring up the idea of breaking up with her, I get the feeling that you don't like the things that you have in common.
What about the things that you DON'T have in common?
Sure you can see what she needs to change about her, but do you see it in yourself too?
What I am trying to get at, the long way around, is that maybe it isn't HER that you really want to be rid of? Something about your post leads me to believe that you are at a point in your life where you want to change who you are, but feel that the only way you can do this is for a clean break from all that you have been. Even if that includes this woman whom you have been in love with for the past 6 years.
Rather than breaking it off with her now, I suggest that you take a week alone... maybe go to the woods and ponder what force is motivating you right now.
I know this isn't what you were looking for, but I hope it helps in some way.
Best of Luck,