Give him some more time. It takes time for fishes to live in an anemone. Also it's not all up to your fish, it's up to your anemone too.
For more info, try reading this...
<a href="http://www.biodiversity.uno.edu/ebooks/ch2.html#ch2" target="_blank">Clownfishes and Their Host Sea Anemones</a>
stupid_naso