Was doing fine until polyhydramnios. Help!

I am bipolar and have struggled with anxiety for most if my life. I have never felt more stable since I got pregnant and found the right medication. But I did just get the diagnosis of polyhydramnios (excess amniotic fluid). There are so many things that can be wrong with my baby and now I cannot sleep worrying about him. My doctor was very concerned but did not go into great detail about the causes so not to worry me too much. Has anyone else been diagnosed with it?