OK, so not really as drastic as PANIC attacks, but just that moment when you are intimidated by the depth and breadth of change you are making. Realizing just how small 429 square feet is. Seeing the mountain of things that never seems to get any smaller no matter how much you sell, give or throw away. The sad eyes of a grandparent who won't be getting daily visits with the kids anymore.
All of these things make the change hard. By this point it doesn't matter how hard it is, it is happening. Too far gone now. Just have to remember the reasons you wanted this change in the first place. Stop letting your stuff own you. Start seeing the world and the people in it. Get out of the big city for a while. See some relatives who are used to annual visits instead of daily.
Take a deep breath and the feeling will pass. Get back to work. So much to do and only so much time in which to do it. We pick up our new home tomorrow. That ought to be a catch-your-breath moment. May it lead to a few take your breath away moments.