30 week scan weight 1.6kg

Went for scan at 30 weeks n baby weight at 1.6kg but doctor said baby is small and its only near to average. So i ask the doctor if its just nice for size. And she said its just near not there. Im like what? So it is really small? Should i be worry? She hope that baby will increase more on the next scan check up in a month. Honestly im about to give up already as 2 wks before at 28wk scan bby was 950g. But still not enough 😮‍💨 Im a small built mummy btw weighing at 51kg(currently) n a height of 155. Sorry for the long post. But im just exhausted to keep pushing the bby weight n size despite eating all the time.