Looking in from the outside

I am starting to feel like an outsider again. Because I am working full time and taking 6 classes I have been swamped, but to top it off I am also starting to hit a depression spiral. I watch as everyone else is making plans, going out for drinks, having dinner, ejoying a "night to themselves" and all I want is to be involved. I don't get invites to the girl's night outs, no one thinks to call to see how I am doing, I havn't been able to see any of my friends in quite a while. I am just so lonely and I feel as though I have been left out of the party invites. I understand that people probably think that I am just so busy they don't want to bother calling, or if I had time I would call them but this is BULL SHIT! Why is it that I am always the one who needs to do the calling, inviting, or just checking in? When I get busy that's it..... I'm scraped from the social list. What the frick! It doesn't help that family takes priority over friends and I have one night a week to actually do something and it always ends up being a family get together of some form. I guess I am just doomed to have no social life.