Hugs from me, too.

Yes, it sucks.

Therapists are good, but also ask your doc to check your vit D levels and iron levels. Changing of the seasons really throws my vit D off whack and I need to supplement vit D to a ridiculous degree just to be in the low normal range. I got so bad last year that my doc put me on antidepressants while she waited for the blood level tests to come back. (the antidepressants nearly killed me, because I wasn't actually depressed at the time) I've done enough therapy that I should have been given a frickin' honorary PhD in psychology, but all the good tricks I learned for dealing with the dumps were useless in the face of vit D and iron deficiency.

One week of intense vit D and iron (CRAZY amounts) and my world was a better place.

It's very simplistic and ridiculously low-tech, but it might be worth checking your vit D and iron now. Perhaps they are playing a contributing part in your cycles of good-oops-good-oops.