Need nutrition help!

I am currently 27W3D. I have lost a total of 18 lbs over the course of my pregnancy. My Ob wasn’t concerned until my baby started to measure small. I have hardly/no appetite and can only eat small amounts. The only thing i seem to be able to keep down is fruit and vegetables, but it’s not enough in calories. They suggested I drink high caloric drinks such as Gatorade, Ensure, or Boost. I picked up a pack of ensure and I had a horrible reaction to it, when I noticed it has Soy protein in it (which I’m allergic to). What else can I drink thats similar that doesn’t have any soy in it ?