just wondering

I'm 33 weeks pregnant and for 3 weeks now I'm back to throwing up just like I was in the first trimester. I rarely eat because it all comes back up, I am able to keep down prenatals and water but usually just veggies and some fruit but it has to be the littlest portion size, anything carb related, greasy, or sugary comes back up either by acid reflux or puking. I'm worried about the baby not getting enough nurtrients and my weight I only gained 20 and it has stayed the same since 24 weeks but I am afraid my weight will start dropping or the babies weight. Any advice?