Yes, I feel this too...even when things are all going well around me I still feel an underlying emptiness/tiredness of life. Like, when things are good I may not feel an active, urgent desire to CTB, but if someone walked up and offered me a bottle of N I'd still take it without a second thought.
For me, my BPD has a lot to do with it I think...I've gotten very good at pretending to be "normal" in front of the world, but going through life like that, constantly having to act like someone you're not, makes existing seem so exhausting and pointless, even when I'm doing supposedly "happy" things. I feel like an actress in a really long, dragging play that never ends.