Help my new anemone?

I got a new little anemone about a week ago, we believe that it is a sebae. It is in my 14g biocube with a couple small bubble anemones doing wonderfully and a couple Percula clowns. The new anemone isn't doing well. It appears bleached (I didn't realize this was not how it is supposed to look), its mouth is gaping, and it refuses to attach to anything either on the rock or beneath the sand. It's open and isn't shriveling up but it clearly isn't healthy right now. I'm worried it won't make it but I don't know what else to do to help it and would really appreciate some help. Thanks!