So, I just read your other thread...
And it is basically the EXACT same thing that happened to me... except my girl and I never talked about marriage...
It sucks, a lot. I did the say goodbye thing, and it worked for about 3weeks. Anyways, I just try to be as happy as possible... especially when talking to her. Act like I don't care what she's been doing and tell her what I've been doing instead.
Anyways... it's nut man. This shit has been happening to EVERYONE I know... and I mean EVERYONE. Including my roommate, myself, one of my good friends... etc...
I just stay busy...
nG