It really is the last resort; even if you were able to find a psychiatrist willing to administer a course of it without extensive trials of multiple classes of psychotropic medication as an adjunct to psychotherapy, your insurer is definitely not going to spring for it. The NHS’ NICE guidelines outline what’s to be considered before ECT is even proposed (https://www.nice.org.uk/guidance/cg90/chapter/1-Guidance#seq...), and criteria are at least as stringent in the US.