Hello Greadlee, and welcome to Parrot Forums! Your lovebirds are beautiful!
If I'm reading your post correctly, you recently bought a male lovebird as a companion for a female that you found on your balcony, and you are now faced with two issues: A) The male seems to have no interest in the female, which has triggered a hostile response as she apparently does not take rejection very well. B) The male has now become lethargic and puffs out his feathers all day.
Okay, a few things. First, having caught that bird on your balcony, have you taken all appropriate steps to reunite her with her former owners? (Assuming you don't live in an area where wild parrots are seen regularly... which would of course raise a whole other set of questions about the ethics of capturing a wild bird, but I digress.)
Second, you haven't had either bird for very long. They should have been quarantined from each other.
All that said, I think that you should get the male lovebird to a veterinarian right away. (Both of them, actually, for wellness exams at the very least.) What you are describing sounds like a bird that is ill. Birds always attempt to hide their illnesses, so by the time you are noticing any symptoms, things might already have become quite serious.
And as for her attacks on him, if they are serious enough you should separate them. When birds have animosity between them, sharing a cage can lead to rather serious injuries.
Please keep us updated on their situation.
