This is exactly how I feel much of the time. And I don't know what to do about it. It's hard to do anything. But I don't have BPD. I can't ever decide what to do because everything seems like a waste of time, but then not doing anything is truly a waste of time. Which is what ends up happening. It's not that things aren't interesting, but they're ultimately not worth it. Existential boredom is the term coined in The Philosophy of Boredom. I even have to force myself to learn how to enjoy food again.
There's a new show in HBO called "Bored to Death" but I'm pretty sure it doesn't have much to do with the subject of boredom.