Kitty,
I have felt the same way with ny depression. I just dont wanna talk about why and I have a hard time plastering the big happy face on and faking it. It takes too much energy and when I get home I just fall apart. In situations that I have had to explain I simply say that this year has been hard for me for alot of reasons, I really dont want to talk about it but I have been depressed and it's a little hard for me to be around people. I hope you understand and I want you to know it isn't that I dont care about you, I just needed some space.
Seems to do the trick and if they dont understand there isnt much I can do about that. Hope that helps somehow. i know it's is pretty akward.
I am sorry you are having such a hard time with things right now. I really dont know what to say. I hope things get better for you.
Heidu