This is the green cheek conure that you found?
What kind of screaming?
What size cage do you have? What kind of toys?
What's your bird mainly eating?
How much time does he spend out of the cage in your room?
There is a lot that can go into causing a parrot to excessively scream. The cage and cage set up and position, amount of time out and interacted with . Day and sleep cycle ...sources of stress like other pets , people, noise and so on . Trust level between you