Two-Timing.

I don't know what to do.  I feel like such a bad person.  The story begins with a girl. I lived with my girlfriend this summer, she is now my x-girlfriend.  I had a really hard time with the break up and didn't handle it well at all.  I did everything in my power to salvage the relationship but ultimately anything I did wasn't good enough.  The reason she gave was that this summer I shut her off, I basically ignored her and slept all the time.  We worked opposite schedules, I worked a 9-5  as a pharmacy intern.  She worked nights at a upscale bar in a hotel downtown.  The summer prior I developed quite a nasty drug habit.  Yeah I know, a pharmacy student with a drug habit.  Anyways, this summer I picked up where I left off last summer, using.  This is why I slept all the time, this is why I was a ZOMBIE.  I finally broke down and told her this a month or two after we broke up.  I don't know why I didn't tell her earlier.  I was to ashamed and in denial I guess...still isn't clear to me.  

Funny thing is...the day I came out and told her this I met another girl.  This girl is a fellow pharmacy student who happens to love all the same music and movies as me...it was weird.  We started hanging out and one thing led to another.  It was going pretty well but about a week later I realized this girl was just another rebound.  She's so nice and I don't have the heart to tell her how I feel.  I'm trying to do it gradually but I can't seem to bring it up.  Then...out of nowhere me and my x start talking again.  I saw her his past weekend...i told my "new friend" i was going home to see my parents...i went to see the x.  We had a great weekend and I miss her like hell.  Now I feel like I'm two-timing. Well I guess I sorta am.  I need to figure my shit out soon..and all this Elliott Smith isn't helping.