I know. I had to endure the same with my sister. She was only 24- tragic bike accident. We gave her one day that way after all the tests- apnea, ear flush, even an additional EEG which we requested and was sparse as the night sky- came back negative. We looked at the weekly costs and made an informed decision as well as choosing some organ donation options.
Watching her wheeled out of that hospital room heart still beating was certainly the hardest moment of my life so far. We never saw the actual 'plug' pulled and i actually prefer(red) it that way.
I deeply empathize that the decision was all on you. doing it collectively was a hair easier. hope your emotional/personal recovery has been as swift as possible.