I think you're right about the contrast - I think maybe just get rid of the pinks on the teeth, the parts of her mouth that aren't the tongue, and the pit of her stomach, and it'll help.
maybe shift the whole pallete a bit? Like:

Added a bit of yellow, +brightness, +saturation.
Maybe you could add something to the background on the right, just above those teeth and below the tentacle, like a boil or something. It just seems like there should be more grey there, for symmetry.
These are all just slight niggles, though. It's really wonderful/horrible as is.