Hi wickedwings
I know side effects from meds can get VERY uncomfortable and down right painful (mentally and physically) but just try to hang in there while you try the new dose. Be sure to call your doctor if anything major happens, including suicidal thoughts, etc, which I'm sure you know but I just wanna reiterate
As for treatment-resistant, I don't know. I'd be very cautious of ECT too. It seems scary to me, but as a last resort, I might consider it. I'm not sure what else to suggest. I have also heard of Vagal Nerve Stimulation, but I don't really know much about it or how it works. I hope you can find some relief somewhere..