Hi - and welcome!
I am retired, so... but I didn't slow down my routine or any projects I had. If I remember correcly the 2nd and 3rd day of the pre-op was the worst for me - I was on liquids only - but by the 4th day I was doing fine. I drank Premier Protein shakes. They are low carb, 30 grams of Protein per 11 ounces - 160 calories, I think. They actually taste pretty good. They come in chocolate, vanilla and strawberry cream. You can find them at costco or Sams at pretty good prices. I had a problem with them after surgery for awhile - my body didn't like whey protein - but now that I am a few more weeks out I can drink them once in a while with no problems.
There are many other Protein Shakes and supplements out there - one I used after surgery was unflavored unjury Protein powder. It is easy to put in stuff like Soup - you don't really taste it and it is about 21 grams of protein per scoop.
I am sure other folks will have more suggestions. Some folks get samples of different varieties to try and choose that way... Good luck with the pre-op diet and your surgery!