Hi Cosbourne,
From what I've researched so far, 15 lbs nice June 19 isn't too bad, especially if you aren't getting the protein needed. Protein, water/liquids, and carbs in the right balance is the key - again, from my research. I hope you are keeping in close contact with your doc so you don't get dehydrated!
I've also seen patients say they can't drink the shakes. One person I follow on you tube, mimmiemeinTN, drinks her shake in the am with a cup of cold brew coffee, and a couple of pumps of sugar free flavorings. But there are so many alternatives to shakes to get protein, like Nectar, Unjury soup, and my personal favorite Protein2o drinks.
I'm also thinking you don't have energy because you may not be getting enough carbs?
Anyway, I hope you feel better really soon.
Keep us posted, ok?