So, because science is awesome (not sarcasm), we know a lot about neurotransmitters, and how certain things affect them. What I recently learned is that taking opioid pain meds, even at a low dose for 2 weeks, tinkers with neurotransmitters enough that when you stop the pain meds, serotonin and dopamine just totally flatline for a little bit while all the various receptors in the brain get their act together and start behaving normally again. It's not super fun.
My medical nerd side is fascinated with how opioids/opioid receptors interact with neurotransmitters. The side of me that is the actual guinea pig experiencing this medical journey is less fascinated and more stabby. Though it does honestly help to know that what's happening is a stew of chemical nonsense in my brain and not a relapse of depression.
A continued infusion of MASH episodes is also helping (I'm on season 10), although I am back to working part time this week, so I am also experiencing Sherman Potter withdrawal.