HELP! Is my anemone dying?

[Delphinus]

Looks just deflated to me. It may be in poor health but there could be other reasons as well. It could have just spawned (they do tend to deflate completely for a few days following a large spawning event), it could be reacting to a change in parameter in the tank (ph, temp, Alk are big ones that can shock an anemone).

Ultimately, my advice is that they are not dead until they are dead. That may sound sorta weird but basically, it comes down to "if you have to ask if it's dead then it probably isn't." (That's not to say that they always live, but when they do perish, the flesh tends to melt into a pile of liquid goo, fairly quickly. If it's not a big ball of snotty goo, then it's not dead, and probably worthwhile waiting it out because you just never know.)

Good luck..