<human>: Here is my situation...
I dated this girl all through high school (freshman year until early on in college). Our relationship was overall  a good one, of course we had our fights and sleepless nights but what relationship doesn't have that? The relationship didn't end on a bad note by any means, we just sort of drifted apart since she had a life a college that i couldn't relate to or be a part of. Anyways to get to the point, during the 3 months of separation i went through many phases of happiness and depression. Unfortunately i finally cracked last night and sent a massive text to her that basically said how much i missed the old days of our relationship. She replied saying i cant keep focusing on the past and beating myself up because she was just as responsible for the breakup as i was. We talked for a bit and now i guess were friends again. 
My issue now is, i don't know how to act around her anymore... For the past 3 months all i have thought about is her and i crave the intimate moments we used to have. Has anyone here made the transition from boyfriend/girlfriend to surface level friends before? I'm experiencing a whirlwind of emotions and i don't know how to sort them out or what to do with them. The main thing that is really hurting me is how well she has recovered from the break up... She acts like a completely different person now, and Im still clinging onto the memories of the old her but i cant let go.

Give me a shortened version of the text
<bot>: I just started talking to my ex of 4 years 3 months post breakup with no contact until now. need advice or words of wisdom.