Djinn, i'm not tryen to be an ***, so if it looks like I am, please don't take it that way. It's hard to tell how someone is coming across when all you see is a wall of text. I was in a similar position before and the longer I sat around the worse it got, as soon as I got off my *** and went out to have fun It faded away quick.
If she really missed you and cared about you so much, why isn't she with you instead of that other guy. Try to go out and have fun forget about her, call up some old friends you lost touch with, see what their up to. She's tryen to keep you leashed, while she's out haven fun and bangen other dudes. Don't sit at home depressed, cut the dam strings, go out and have fun. The sooner you go have fun the quicker this feeling's gonna go away.