Have you seen one of these before ?

Try getting some kind of natural live food and leave it in there overnight. Maybe she would like to hunt for her food. If she goes and hides she will eventually come out when you are not in there and hopefully feel comfortable and eat.

Looks kind of like a Dog-Toothed Cat Snake. Pretty cool looking, whatever she is!

I agree with Tikka2506...

I got my Dumerils boa to eat again after 6 months(!!) of hungerstrike by adapting my cage a little to be more realistic to the natural surroundings they would be used to in the wild... And most importantly: I left pinkies and fuzzies in the cage overnight! About 2 months ago I was delighted to see that one morning the pinky I left overnight was gone! It now feeds on pinkies and fuzzies of rats, mice and hamsters...

So, leave the snake alone for about 2 or 3 days, then leave about 3 LIVE pinky mice in the cage overnight and leave the snake alone again for a while. In that way, the snake has minimal stress and it can decide for himself to come out whenever he likes...

The pinkies will live for about 2 to 3 days... Worth a try, ik worked for me!

And about the nervous behavior, just handle the snake a lot, but I guess I don't need to tell you =D My Dumerils boa also was afraid and was in panic when I slided open my cage... Handling him often just helped...

I am really surprised that no one has mentioned this yet, but have you had her vet checked at all? She my have parasites....ESPECIALLY if she is WC. That could be a good reason why she is not eating. I also agree with feeding tree frogs btw.

...that is definitley an epicrates, and probably a gracilis to boot. I have two haitian epicrates (E. striatus striatus) and they are usually fedby leaving a dead mouse at the entrance to their hide box overnight.
I'm not sure what E. gracilis eat, but the species account references two sources for husbandry information. If you can find them, they would probably be pretty helpful.

one is: Tolson, P.J. 1994. The reproductive managelment of the insular species of Epicrates in captivity (p. 353-357) in J.B. Murphy, K. Adler and J.T. Collins (eds.), Captive Management and Conservation of Amphibians and Reptiles. SSAR Contrib. Herpetol. 11, Ithica, New York

the other source is: Walls, J.G. 1998. The Living Boas: A Complete Guide to the Boas of the World. T.F.H. Publ., Inc., Neptune City, New Jersey.

Hopefully you will find some of this helpful.

Typical food for gracilis are anolis lizards.