Sleep (or lack thereof)

Saturday night.
It's 9:00 in the evening, I'm sitting in the downstairs office, my hands are shaking and I'm trying to control my breathing because I want to be sick.
Going back a few hours.
7:00 am Saturday morning. Waking up it's like wading through badly made porridge, I can barely string words together, I think H (my partner) has brought me several cups of tea, none of which has had any noticeable effect on my ability to function. I've managed to make a breakfast for us both, I'm quite sure it wasn't exactly what was planned but I maintain that it was for the best that I ate something.
I'm at the restaurant, I'm helping, not as much as I might have hoped but still I'm contributing. Lunch is looking busyish, we've got a decent complement of kitchen staff in for the day, I can hover on the wings of service. I'm liking this, I can watch, satisfied that things are progressing as hoped, talk to the tables that need talking to, absent myself when necessary.
Post lunch service it becomes clear that things are about to change, one of our chefs has to be away that evening. Her brother's 30th, or some other similarly unmissable family occasion.
This evening, I'm crossing the pass.
The pass is like the Rubicon of the restaurant, it delineates two very different worlds. On the one side the graft is primarily physical, non stop food prep and service, yet cut with a need to be mentally acute enough to keep track of a host of different activities and needs. What checks are waiting, what checks are away, what's on the grill, what ought to be on the grill. When it works well it's a model of conservative action. Talk is limited to a minimum, only the most pertinent issues are raised. There's a steady stream of updates and questions. All relating to what is being done and what ought to be being done. No one minds if you're not smiling, so long as the food is coming out, smiling can wait.
On the other, the facade is king. You might be running, juggling several tables and trying to balance multiple guests requests, but thankfully there are far fewer knives.
Front of house fatigue endangers the fingers far less.
The call comes.
We're one down tonight, can you step into the kitchen.
I'm not a chef.
The restaurant is mine and my partner John's. It's John that's asking.
I've worked shifts on the pass quite a few times before, it can be quite fun. It's amazingly satisfying when it all comes together, however it's not something I find easy.
Front of house; I can bang out a shift in all sorts of states. My game face is great; hangovers, fatigue, all the trade's inherent issues are easily navigable. I've got years of practice. While I've never actually done it in my sleep I've come pretty close.
Crossing that fence however. Much less easy. We're pretty busy, the little white printed tickets keep arriving, I don't seem to be brandishing the marker pen. What was originally two tables worth of starters seems to have mushroomed into five. My all day counts are rising, but I can't seem to hold more than one number in my head at any one time. The assertive persona that I try to adopt when at the front of the kitchen is being strip mined of any effectiveness by my almost complete inability to grasp any inertia. I take some plates out of the hot cupboard. Look for garnishes. Ask John whether he has the requisite things on the grill. I put the plates back in the plate warmer. I've got no fucking clue what garnishes I'm supposed to have heating. Christ, I'm having to keep checking the pass to remember what dishes I'm supposed to be serving.
It's 8.45pm. I've gone to look at the iPad till, hoping to see 10.45pm, knowing that's not what I'm going to see. I'm looking at the reservations diary. I can see another wave of tables. I can't do this any more.
I look at John, I try to put my case across that I'm sure I'm being less than useful in my current position, that of being in charge of the flow of food out of the kitchen, it's plating, and generally the organisation of said kitchen's work flow.
He pats me on the shoulder and says 'ok'.
I'm getting changed.
It's 9:00pm.
Getting into a taxi to go home, the only thing I can think is that I've only worked 12 hours straight. At least I'll be ok to be back in for 7am. It's Sunday tomorrow and I need to get the mangal going early for the spit roast.