Fluid in babys head (long post)

Today I had my anatomy us . I'm 19 weeks pregnant and everything look good we even found out the sex of our little one ! A boy . After the scan was done the technician told us the Dr was coming to talk to us. My silly mind though the Dr was coming to double check the gender ( the baby was being shy and the technician never got a clear shot but was almost 100 percent sure with what she could see) Anyways the Dr comes to the room and starts scanning again. Hes not talking and just looking at his screen and double checking things . He stops and shows us a close up and tells us our baby has fluid near his cerebellum and it's not that common(the only see it like 3 times per year) but it's not that rare either . He recommends a fetal MRI so we can make sure everything it's ok and what to do if there's indeed fluid . My heart broke ! At this bad thoughts came to me and I start crying non stop . I was so bad that I almost had a anxiety attack . My dh went back to the office to question more. The Dr told him it's not that serious and that the baby is healthy they just want to make sure how much fluid there is and what's going to be the next step. I just want to hear some stories about it if anyone had this issue before. I'm seriously panicking ! I'm want my baby boy to be healthy

UPDATE it's call Blake pouch cyst 😔 there's no much information in the internet about it . Still doing the MRI to see what are the options