Overly full feeling??

The last two pregnancies I have felt this way. I can only eat one bite at a time with whatever I eat and I feel like I am so full I am gonna puke, I get a knot in my throat and it's hard to swallow without feeling like I'm gonna get sick. The last one was the worst, the night I had baby I are so much and ran the nurses ragged bc I hadn't eaten in months (literally) and I feel that way his time again but not as bad. What causes this anyone know??