I think you do need a break you are asking a whole load of questions no-one can help you with. e.g. whilst it is normal for the passion to fade do we actually have anything other than friendship left in this relationship? are we causing eachother more angst by being together than we would by being apart?

Breaks are cruel though. Is there anyway that you can arrange to be somewhere without her where you can think clearly? Go home to your parents for a week and decide at the end of that time you have to make a decision one way or another? That's another thing, at somepoint you are actually going to have to be firm with yourself, make a decision and stop agonising about what you've done. Yes it may be a mistake but you're human you make mistakes and you just have to learn from them.

Hmmm, don't really think that was much help, just me wittering on, but never mind!