Wow, there have been some really good, practical, doable suggestions here.
I'm sorry Conquer, I relate very much to your current struggle and to all the reasons why the things you"should" do so often aren't the things you "can" do.
I think SweetPea gives some exellent advice, and I also like the tape-recording of affirmations, in either your own voice or the voice of someone you trust and respect.
I know exercise can be hard, even though there is absolutely no doubt that if you can achieve it, its mood-lifting qualities are astounding. Sometimes a compromise is just to get some fresh air and sunshine, so if there's a balcony or outside area you can go and sit for a while, those natural qualities can be very calming, restorative and energy-enhancing - I have become a sun hog, and find much comfort in it. It might even give you the tiny nudge you need to go for a short walk, but if not, that's ok too.
My therapist encourages me to think about what gives my life purpose and meaning, not in the sense of grand achievement or markers of success, but the things that make you feel as though you are living true to your values. Maybe you like helping others. Maybe you like being creative. Maybe you like solving problems... whatever it is, spend some time thinking about it, and looking for even tiny ways in which you can pursue those values. It sounds a bit abstract, but it actually does help - when there is no hope, even a tiny bit will get you through.
And keep writing here... that's what I'm doing, because it helps, and it brings not only activity, but also human connection, accountability for still being here, creative stimulation, the potential for new ideas and things to think about, and a chance for you to be in a validating place with people who understand.
And go easy on yourself... often the hardest thing. Those who haven't battled depression will never know how dabilitating it is, or how lonely, but they will also never know the determination and courage that will pull you through it to the other side.
Maddog