I think these are generally quite depressing times, Sweetleaf. Just reading a newspaper these days requires fortitude, because there is so much bad news, so much horrific stuff, and it all adds up, chipping away at our personal reserves.
So it may be contextual. Or maybe it is signalling some need in your own life whose time has come? Sometimes these vague depressions, I find, occur just before some kind of realisation that moves me on to a new stage of my life or the way I want to live it.
I have noticed for the last year or so that your posts were more mellow and thoughtful than the years before that, though that's not to mean that they weren't thoughtful before that.