Dont take this the wrong way... But i get the feeling u didnt do much research before investing in your anemone?
As stated anemones need lots of light and a very established environment before being introduced to a system.
Just a tip for the future, make sure you do vast amounts of research before any purchase, whether its a fish, coral or anything else you want to introduce into your marine tank.
As for ur clowns being hosted, it can also depend on whether you clowns have been tank bred. As that will hinder the chances dramatically as they don't no what there supposed to be doing. Where as wild clowns do...
Give ur anemone time to adjust, i have 2 in my tank. My BTA stays in the same place all the time, but my other one moves around and stays behind rocks etc. but hes still doing well and is very healthy!
Good luck!