When the coffee line is out the door, you make the next drink, not the whole line.

Looking at the whole queue produces panic and no progress. The work can only be done one item at a time anyway, so holding the total in your head adds nothing except the weight of it, and that weight is what makes people freeze or rush. Narrowing your attention to the next thing is not avoidance of the scale of it. It is the only method available.

When the pile is overwhelming, cover it over and look at one item: this drink, this question, this box. Finish it properly before you lift your eyes. Count what you have cleared at the end rather than what remains in the middle.