Good luck on your surgery!
I hope everything goes according to plan. My best advice would be to follow your surgical team’s instructions to the letter. Preop diet is very important, so you should be very strict about it. I am a just over a month postop, and, for me, the hardest thing was my food grieving process. As for the moment, the hardest work has been psychological. It did feel like losing a friend, or perhaps a safe space. However, right now my cravings are almost gone and it ha been increasingly easy to want to chose healthy food. You might feel some regret the first few days after your surgery, as food intake can be challenging, but I promise it will pass. My recovery has been fairly easy, so I lucked out. One piece of practical advice would be to eat (drink) much more slowly than you think you need to, and to pause frequently. In my case, sometimes I take bigger bites than can comfortably pass down. The first few weeks this can be quite painful. You should be mindful of these details.
Be patient with yourself. This is a lot of work, but pretty worth it. Also, walk as much as you can after you wake up from surgery: it decreases gas pains by a good deal.