Try not to overthink it right now. The ECT will be jumbling your thoughts, and the fact you’re ill enough to need it means you’ll be struggling to think straight too. Long term plans can be addressed once you’re over this hump.
One day soon, you’ll wake up and it will be like a break in the clouds. That should not be far off now, even if you relapse a bit and need a top up. 6 sessions sounds like a minimum, I’d manage your expectations and say you’ll feel significantly better by 12. Hopefully, you’ll then be surprised by it coming sooner!
Waking up from a treatment is always grim for me. Headache, sore jaw, dehydration. Don’t measure your mood at this point. Reflect on how you feel the day after, or the day after that.
I had many diagnoses running both concurrently and sequentially: atypical depression, anxiety, OCD, borderline personality disorder, dissociative disorder, to name a few! 30 years into my journey as a patient, and with a fixed diagnosis of bipolar disorder for nearly 10 years, I wouldn’t worry too much about the diagnosis. You need a doctor (or team) who knows you as an individual and will do the thinking on your behalf, while you are ill.
I also tried more meds than I can remember, multiple types from many families of drugs: antidepressants, mood stabilisers, antipsychotics, regular anti-anxiety, beta-blockers, benzodiazepines, sleeping pills. The ECT is the only thing that has ever shifted a deep dark depression.
Do you have someone at home with you between treatments? One series that I had was an outpatient, and I had moved home to be looked after by my Mum, who took compassionate leave from work. I definitely didn’t have the capacity to look after myself. Bless her, she’d try so hard to get me up every day between treatments. It was this time of year too, so she’d take me to a family farm to see the lambs or for a drive in the countryside, just to try and raise my spirits.
You are going to be ok. Statistically ECT is so much more effective than any of the alternatives, when dealing with treatment resistant depression. You know the risks and side effects, but you’re doing it anyway. 5 sessions is a good few, so that break in the clouds could come any day now.