Fukuoka pre-race panic

it is only a mere 17 days to go to my Fukuoka Marathon.
everything seems to go as planned (training, health, race results), but I am assailed now by a dramatic pre-race panic about being able to complete the race.

Because the main trick is that their cut-off time is a 2h45' pace. Every 5k, they have cut-off at 3'55"/km pace and if you are too slow .... race over.
For a 2h40' runner like me, basically means that even a toilet stop in the first 10k would already put me out of the race ...

Most of the marathon in Japan are for "elite" runners: entry fee is very low (only 20$ for Fukuoka) but the entry requirement is a recent PR under 2h45' or less (was 2h30' for Tokyo)
Fukuoka has been for long time one of the most prestigious marathons and the winners list is impressing (Frank Shorter, DeCastella, Densimo, Dionicio Ceron, Seko, Thugwane, Gebre being the last ..).
In Asia it is recognized as the fastest course (give a look here)

Said that, for a "AlsoRun" like myself, I would feel the pressure to be basically almost dead last and having to push like hell just to make the finish line. I can not imagine to fly back home saying to my wife that I was out after 30k because too slow ...
The main advantage it is probably one of the few races in the world where the starting pack is small (300/400 at the most), and many runners would be close to my level, so I hope to run in a pack as much as possible.

I am really starting to freak out on this ...