That started me Googling and I soon found Cyclothymia which is, you guessed, a milder version of bipolar. I've carried this self-diagnosis for some time, but then came some pretty significant depressive episodes, some therapy, and a trial-and-error clown car full of psychotropics and anti-depressants.
This week I'm at the psych's office for the semi-annual review of how marginally the drugs are working when I mention my self-diagnosis. He tests me, I'm positive for it. Meds are changed to ones more suited for cyclothymia than depression. Some of the meds I've been taking can even exacerbate cyclothymia.
Hope springs eternal.