I'm sorry that your question wasn't answered in a timely manner. We don't have many avian vets on this site. I'm concerned that if you're not seeing droppings that your conure hasn't been eating or it's eating but its crop isn't emptying or its gastrointestinal tract has lost its motility. In either event, your conure would be quite ill and in the need of an avian vet such as can be found here: www.aav.org.
It's important to note that once a conure acts ill they're quite ill. This is a protective mechanism because sick birds are attacked by other birds in the wild. Your conure's symptoms are important but they're not pathognomonic (specifically indicative) of any one disorder.
An avian-oriented vet might first treat symptomatically and supportively by providing supplemental fluids and electrolytes by needle and tube feeding a "recovery" food. Blood tests and cultures of your bird's choana - the slit between her oral cavity and nose - and cloaca (vent) may be taken.
Until your conure can be attended to, please heat up its environment to 85F by means of a 100W bulb shined into itspartially covered cage (not at night when it needs to rest) or by taping a heating pad set on its lowest setting to the sides of its cage. If it appears weakened, remove its perches and put its food and water on the bottom of the cage along with it. Add a water soluble avian vitamin such as Oasis brand to its water at half of the recommended dose so as not to make its water distasteful. Add a calcium supplement such as Calcivet or Calciboost to its water. These supplements are available in pet/feed stores. Avoid over the counter antibiotics designed to be placed in its water. They won't be effective if only because an ill bird won't drink enough to medicate itself properly.
Nutritional imbalances are a common cause of illness in our pet birds. What has its diet consisted of, please? Seeds should compose less than 20% of its diet. Ideally, a balanced pelleted diet such as can be found here: www.harrisonsbirdfoods.com or here: www.lafeber.com/pet-birds should be fed as well as hard boiled egg yolk, pancakes and cornbread, the tops of fresh greens, dairy products such as yogurt and cheese, fresh fruits such as apples, pears, melon, kiwi, and berries, vegetables such as broccoli, carrots, beets, asparagus, cabbage, sweet potato, and squash, and even tiny pieces of meat.
Is your bird male or female, please? Please respond with further questions or concerns if you wish.