Distract yourself with everything you can. The pre-surgery diet is universally the hardest bit, and everyone just has to soldier through it. The first week is the worst, as it's pure cold-turkey and that means withdrawals from carbs and sugar which are rough. Ask your team if you can at least eat vegetables for some texture? If not, find any distractions, whether it's walking, reading, playing games, doing some DIY.
It feels like forever when you start it, but the time does go. By week two, my looming surgery brought pre-op nerves that helped distract me from the starvation diet.