You can’t get back the hour you scrolled. You can still decide what the next hour is for.

Time already spent is gone and nothing you do next changes that, which is a small loss next to what people usually do about it. The real damage comes from writing off the rest of the day, deciding it is already ruined and the following hour may as well go the same way. One hour stays one hour until you decide it was the whole day.

When you look up and the time has disappeared, do the next small useful thing straight away: one page, the washing up, a walk. Skip the part where you tell yourself off. The next hour is the only one still on offer.