Low amnionic fluid, baby not growing

I'm sooooo stressed I don't know where to begin, 😔😔. At 19 weeks of pregnancy my doctor noticed that I had low amnionic fluid. He changed my hypertension medication and said I should come back after 2 week. Today he told me that the baby is not growing. The baby is closer to 400 grams and by how far along I am should be chasing the 600 grams mark. I felt so defeated, this baby comes after a stillbirth of the 23rd of September 2021. Any ideas on how to increase amnionic fluid and baby growth in-utero would be highly appreciated. Please do not leave your prayers behind for my situation, we need God's intervention. Thank you in advance as you reply, 🙏🙏.