I have had that happen many times, I blame it more on my crazy hormones (I am pre-menopausal) which have made me feel so moody, wacky, depressed and agitated and then "Poof"! I go into neutral.
It can be that I am BP-II Mild too besides pre menopausal.
I think my mood stabilizers do help keep things from getting worse, but I guess the answer will come once menopause and things come to an end, who knows?
It is strange how our moods can mess us up, I sympathize with you, this can suck at times.
My advice is to talk to your pdoc about this, it may be a physical thing rather than mental or a combo of both, and there are quite a variety of meds that can target the problem, don't give up faith, okay?

((((((((((((( for you )))))))))))

Lots of luck,
DE