I'm more like you in this, atomic, in that I have short-term various (2-5 or so days) states - including depression bouts (as well as daily moods) - within longer-term cycling. I've not been diagnosed, but it gets more and more convincing (to my husband as well as me) that I'm BPD with moderate cyclothymia.

I haven't felt like ending it all for a little while, but I sure am hanging out to just feel some confidence and motivation again - so I can actually DO some interesting and worthwhile things!! (and feel like an interesting and worthwhile person)