Head measuring small

I’m 30 weeks pregnant and just had an ultrasound on Monday and the dr told me that the baby’s head is measuring really small under the 10 percentile and that the rest of her baby is bigger and measuring normal. The dr is having me up my calorie intake and protein intake in the hopes that it will help her head growth catch up, but is still concerned and is having me do another ultrasound in 4 weeks to look at her head and take measurements again. I’m totally losing it and so scared and stressed and worried and it’s hitting me in waves and making me feel like I’m a total mess. I’ve already looked into microcephaly and I’m so scared and terrified that’s what it could be! Anyone have a similar situation?