I..sleep, a lot. Usually on bad days, I can't muster much energy to do anything, not even play with the dog. I get very needy. In the past, when I was younger and not really savvy in social dealings (I have Aspergers) I'm sure I weirded people out.... reaching out to people who I wasn't all that close with. I tend to keep it in, now. I used to post a lot on an Asperger's forum, when I needed to reach out. I usually just call my dad these days. On bad days, I either live on my computer or phone-- talking on here, on FB, or to my dad. Neither my husband nor I communicate feelings well, and usually he thinks I'm out in left field (he really does try, but gets frustrated that he can't help, and then I get frustrated).
I used to get even more depressed by the fact that I'd wasted a day, but since my AS diagnosis I've learned to just think of it as isolating myself to recharge my batteries.
I don't consider myself a religious person, but when I get super down/desperate I have the urge to go talk to a rabbi, for some reason. Why a rabbi, I have no idea-- my family was very (very) loosely "christian"... but my neighbor was a rabbi (or whatever the female version of a rabbi is) and I used to talk to her a lot as a teen. Maybe I associate it with peacefulness.
Usually I just try and talk to people online and wait it out. I hate that I can't ever do anything-- I feel like I'm made of cement.