[Ganrin]

It doesnt look to be dying yet, Its well footed. I cant really tell is the mouth nice and tight?
Does it move around a lot in your display, or did it find a spot and stay there?
What foods are you attempting to feed it, many anemones have a specific food that they respond to and will ignore others, My first LTA would only eat fish, totally rejecting krill, mysis and other food particles.

When new to a tank many anemones will draw in and expell water till they are used to the water in your tank. I would try to reduce the nitrates if you can but that usually happens on its own over time as long as you arent over adding nutrients.