Yeah, I'm finding that what used to keep me interested no longer holds my attention for very long. And TL, I get something similar where I feel like I should be doing something important (and sometimes there is a specific thing, sometimes not), but instead of replacing it with something, I just don't do anything.
I have a few friends I hang out with regularly, and when we hang out, it's fine, but if I'm by myself, I'm bored out of my mind and just sit around on my computer doing nothing.