Growth Ultrasound This Week

So my baby's abdomen was measuring very small when I went for a 21 week ultrasound so now I have to go back in a few days when I'm officially 24 weeks and see if Ive gotten better the last 3 weeks. I'm very scared and they said I will be high risk if she doesn't get better soon. But I'm just nervous and need either kind words or good advice. I've been eating more nutritious foods and eating more often now that I'm not as sick. And drinking milk and all types of stuff. Trying to control my stress as well because that also effects her.