I'm with backup, this is pathetic, both the way she is acting and the way you're handling it. You're acting like a 16 year old who was just dumped for the first time.
you had a great 6 months, and the relationship ended. Most relationships do at some point or another, and many end in a lie because one of the people doesn't have the balls to tell the truth, which inevitably is "I don't want to be with you anymore". All the letters and actions point to this, she has told you "I don't want to be with you anymore", in a 4 page letter, and through body language. The worst words you've heard are "...right now", those are universal cop-out words to let someone down easy, but cowardly in the way they leave hope where there is none.
My ex told me the same stupid crap, we dated for about 10 months and she broke it off saying "I still love you but I'm not ready for this relationship RIGHT NOW". She called and wanted to talk for weeks, then one day she was with someone else. There was another member here "DarkHelmet82" who went through the same heartache. He dated a girl for a couple of months, then she said she couldn't be with him right now, and he waited and waited, and she started seeing someone else. It destroyed him - don't let yourself become that person.
Time to move forward and stop wallowing in self-pity and telling yourself things you only want to hear. Game Over, if she comes back to you, then cool, and if not, then move on.