The best thing I have found for those of us who are diagnosed as treatment resistant, is to jump way outside the box and basically learn what therapists learn. Understand the principles, understand everything you can about psychology specific to PTSD aspects and all it entails. Yes... it is a lot, but it helped me and others the same, significantly. Then there is simply time, with lots of pushing oneself, trial and errors made.Do you have any ideas "outside the box" that may help?
Do I still have PTSD problems? Absolutely... but I can function to do most day to day things, and then some, and manage myself quite well. Yes, I do still get sick from time to time where things go to shit, but for the most part... all is well and manageable if I control my environment and exposure to others.
I can go to the shops without issue, clean the house, walk my dogs, interact with others without issue, drive without killing anyone, so on and so forth. Rage and symptoms stopped me doing most things in life prior, usually just tucked away at home.
Even my wife having employee's around... a couple of years ago I couldn't take more than a couple days a week. I would start melting anything more than that. Two years later, gradual exposure, more self work and putting logic into place... I have people around me most of any week now, no repercussions as a majority. Took a couple of years just with that, but there now.
Lots of knowledge, lots of hard self work -- that is really the key. So yes... with all of that, comes time. Take on something, when corrected / best as it will get for that time, move onto the next thing.