Doesn't look good. Looks bleached also. Only good sign is that he is still holding on to the rock and hasn't gone face down or for a float. I'd move him to a QT tank if possible, with that rock if you can. Don't want him to release and end up in a powerhead, I've been there and it sucks! It would give him a break from that clown too.
How are your water parameters? If they are clean and stable he might just need some time to recover from your clown and the fish store.
I have a carpet anemone starting to deflate and gape it's mouth, I'll be moving him to the QT I setup after work and treating him for a bacterial infection. Apparently it's fairly common with them.