I am so sorry you are going through this. Breath, seriously take lots of breaths. Did your doctor not explain what a fistula is? You can get some good information from the CCFA website and other resources. I have had fistulas since I was diagnosed and they are not fun, but they certainly are not the worst Crohn's symptoms. I currently have two setons in place to help close them and also started Humira last week (I previously did Remicade but it stopped working). You are not alone! Make sure you ask lots of questions and try not to panic. It will be ok. Hang in there!
Beth