Can someone assure me day one matters?

It seems everyone gives up on day two or three. I'm on hour 16. My symptoms started at hour 5. It's been a rough day and discouraging to think this this is the "easy" part. I'm coming off 7-oh. I'm sweating through my clothes, pacing the floor, cold chills. Do most most people really quit on later days because it's harder or do most people give up day one and just don't report?