Your lights aren't enough to keep an anemone. If it's not dying already, it won't survive long term in your tank with those lights. I'd look into finding it a new home, while there's still a chance it can recover. If it was not attached to the rock very well, that is a sign it's sick. I'm glad you got it out of the tank early though -- there is always the potential for them to wipe out the rest of your tank, so good decision there.