Suddenly terrified cat, help!

So yesterday my cat was laying on the coffee table as usual, and I got up to turn off the ceiling fan. She all of the sudde. Started frantically gazing at the ceiling and then sprinted off into the bedroom where she hid under the bed. Since then, she has been under the bed. Going on about 36 hours of this now. She freaks out if the fan is on or off now. She isn't really eating much either or drinking much. I don't even think she has used the litter box because she's so scared. Every once in a while she will peek her head out and gaze at something with wide eyes and then hunker down under the bed some more. Any suggestions or advice is welcome!

Can you cover the fan up with a sheet or something similar? When she's been like herself for awhile you could gradually uncover the fan very gradually. Then it would be a matter of feeding her treats and playing near it to give your cat the idea that good things happen in the vacinity of the fan. 

In the short term, something like feliway may relieve her stress for the moment. You'll need to move her litter box, food and water close to where she is hiding just while she is hiding.  

Soft talk and gentle interactive play and treats may bring her out from under the bed. If you have a cat tunnel you lay it down near the fan in the short term so she can traverse past it. I'm not sure it would work but it's worth a try.