Do you have a QT? Maybe get the little clown in a seperate QT by itself in order to watch it , let it have time to heal by itself and treat for bacterial infections if needed. Also being by itself in a QT will allow it to get more food. Try some frozen or live foods if hes not wanting to eat. Those will usually tempt most fish. Most fish can go a while without eating, but we should try to find out why hes not.
Post a picture if possible, so we can see whats going on and try to help more.
75 Gallon Saltwater Reef
Just your average LVT (licenced vet tech) trying to help the world's animals!!