Your cuddly baby is disappearing and he's starting to assert himself. That's good for his self esteem. Don't take it personally, it's a gift when he does want you to pet him. He must still step up when you ask though, just be cheerful and persistent.
As far as screaming, I would play peekaboo around the doorway corners or do something silly like that before he got a chance to start. When he's out of his cage do you always carry him from room to room with you? Maybe try peekaboo while he's out of his cage too. Will he stay where you put him? Kito's thing was digging, and as soon as she started I would change something in her environment - give her something to do and bring her out for at least a few minutes or bring her to another room. He's still just a baby, and I don't know crap, but I never believed in letting my human baby cry for 30 minutes either. Other things I would try - change his routine, rearrange his cage, make sure he has all differrent types of toys, get a small sleeping cage in a quiet part of the house to make sure he is getting enough sleep at night (12 undisturbed hours), bring him out and put him back in his main cage many times in a day for varying lenghts of time, hide treats in lots of different places in his cage, leave a tv or radio on for him when he's alone, last resort - get him a pet parakeet in a separate cage near his.