Yes, it goes away immediately with the first time your dick surprises you.
A few years ago, because of a course I was taking on harnessing flow, I gave up screens for various months. That was related to facebook, instagram, and other distractors. However, inadvertently I stopped watching porn during those three months too. I didn't know about PIED and had experienced a few incidents of ED that I thought were related to the psychology of a bad relationship I was in. Whatever the cause, I was left with this terrible performance anxiety. Will it work, won't it?
When I gave up screens, I also broke up with that girl and for those three months or so, I did not date. When I started dating again, my PIED was gone and my following relationship was characterized by good sex without fail. Not once did it not work. I just thought I was that much into the girl. And also, because the no-screens thing worked so great in other aspects of my life, I continued with it. However, I didn't know quitting porn was the reason my boners were working so great, hence the reason I'm back here, because a couple of years after that I broke up with that girl, I came back to porn and to ED episodes for many years (so much so that I never made the connection to porn until 14 days ago, go figure).
But I tell you my man, to answer your question:
Yes, that one time when it works perfectly gives you your confidence back, immediately. In one go. Unlike PIEDish viagratized boners, that healthy boner feels so different, like nothing can threaten it, that all your previous incidents get erased by your feelings of manliness and your anxiety becomes non-existent instantly. Just, when that happens, never ever watch porn again. Ever.