Kathleen, don't stress too much. You still live pretty close to your chapter, don't you? I know it may not help without having them around all the time, but things will get better and, although this is a little depressing, the lack of people you know may help you focus on your midterms.
I totally understand how you're feeling though- I became pretty depressed after graduating. Although I don't live far from campus and haven't gone anywhere yet since graduating, I experienced the lack of a social life for a little while. Not that I couldn't call people up, but I felt like the alum burden on my sisters, so it took a quite a bit of persuasion to get me out.
Things will look up... and you always have us on GC...
In IIKE, Carol