Food not digesting, just sits there

It feels like there is no room for food and I am only 19 weeks. Digestive system is just stalled half the time, like the food is being blocked from moving out of my stomach properly. I get hungry but can only eat a few bites of food at a time. I get nauseous if I try to eat more, even though my bad 3 months of morning sickness is winding down and I can at least cook and look at food again. I haven’t gained any weight yet, even though I am showing a ton and this is my 2nd pregnancy. Sodium pills make some movement happen but I need more calories! I’m hungry!