attempts to be social

My mom was getting "very concerned" about my anti-socialness, and wanted me to try to integrate myself back into my friend group. They are all still my friends, but I have done a very fine job over the past six months or so at completely shutting myself off from them. So these past few weekends have marked my attempts at returning to the way I was, busy all weekend with my friends.
Last weekend's attempt was obviously failed to an extent, because I was so sad at the party. Last night Shauna came over and we talked about a lot of things, and the two years that passed since she first sat on my bed and now. Remarkably, we can still have the same conversations, which sets her apart from any of my other friends. Altogether, it felt really good talking to her, I always forget how much I miss her when she's gone.
Today I hung out at coffee shops and at Perkins with some random people... Sean, Stevie, Kyrstin, etc. It was fun, I suppose, but I can tell it's going to be hard at first, this social stuff. I remember driving around aimlessly every weekend with Siobhan, Kyrstin, and JoAnna, and I miss it, we had so much fun. So although a part of me is apprehensive, a part of me is excited about trying to struggle back into my old friendships.
I have even rediscovered Sam... I can't believe how much I've missed him as well.
I think my main problem is that my carefree days of parties at my house and pizza and prank phone calls from middle school are over. I feel like I don't even exist as a human being. I feel my body, and see it in a mirror, but secretly I actually believe that I cannot be more than an apparition, I can't possibly be flesh and blood. Too much has happened, too much has changed, for me to have lungs and a beating heart the way that everyone else does. I feel unique, and so far away from them, because they exist, and somehow I don't, not anymore.