Sorry you are feeling this way, I used to. You may need to face some of your fears of the past to be able to mentally tag the stress on them, and not new events, (new events should trigger stress, but not thru the roof).
Also face common stress with a list of what can happen now, like will i die from this, no, does this stress seem too much for this situation, yes, is this stress from my ptsd rather then the event, ?, and make sure, like i do, to try to ask very silly questions in the end, to cause laughter, this for me seems to bring down the stress, releasing it, and making it possilbe to lessen it for the next event of stress. Like do I feel gassy, or does this stress make my rear bigger? Stupid stuff that cause laughter.
Hope these suggestions help, another ptsd ed person, White Wolf