OK we are moving way to fast on this system.
1. Did the tank ever fully cycle?
2. A 10 gallon tank is no place for an anemone.
3. An anemone is a photosynthetic animal, and all of the hosting types will require PC, VHO or in many cases MH lighting in order for them to survive. Standard lights are not strong enough, nor in many cases have the proper spectrums for an anemone to live long term.
4. Ammonia is a killer, if you can't control it fast then:
This applys to 2,3,4 my suggestion would be to take living things back to the lfs if you want them to live.
You have to have a fully cycled, near mature tank if you want an anemone, then my suggestion there would be to have at least a 29 gallon tank if you must have an anemone. you must also have proper lighting for the type of anemone you want, and even that is subject to debate on the lighting.
I'm glad you know your mistake was moving to fast, and please slow down. your certainly not the first and you won't be the last. Just take it easy from now on, and if ever in doubt check here before you do or add anything. Lots of good folks on this board willing to help you not make the same mistakes that many of us have when we first started.
Thomas