Ugh weight loss

Cynthia • Married :) 07/20/15👶 02/25/17👶 expecting an IUD baby oct 12th ‘19
I'm 31w and was diagnosed with GD since being in the low carb diet I've lost 4 pds. I hate it, I feel like I can't get enough food that follows the guidelines I have to follow
My little man was measuring 1-2ws small already, and I don't want to make that worse. 
I have sucked at eating this whole pregnancy I lost 10 in 1st trimester, and gained that plus 6pds back, but now I'm only at 2 pds weight gain for my 3rd, ugh...I'm just so frustrated and once again I have no desire for food...I force almost every bit of food in my mouth.
Just a rant, but if you have advice please share