He should be eating and angels do like to eat and they usually aren't shy about it either. Make a close observation of the fish and his behavior. You say he is swimming around alot. Some fish dart and swim alot when they are ill. Look at his scales, breathing and specific tank behavior. Is he being harrassed or are there other too aggressive fish that aren't letting him get his share of the chow? Take a day or 2 to observe him. Also, if you haven't already, offer him other foods that you haven't offerred. Some fish are picky eathers! What are you offering in the way of food? Oh, and a word on "observing" fish, especially when you are trying to check out appearance and behavior....try to look without being seen. LOL In other words, you can't check out the fish's behavior if his behavior changes because he is nervous about you looking at him.