Hey guys! Im new to this forum, so sorry for any awkwardness. Anyways, I recently bought a two month old cockatiel

from a local pet supermarket. I named him sunny because of the way the yellow kind of fades throughout his body. I got him and the first few days he didnt do anything. He started eating after two days, and now hes eating better. Whenever I give him a sunflower seed in his cage, he sometimes eats it, sometimes he flutters away. His cage is next to the parakeets' cage, and theyre all in the living room. I try to leave the cage door open so he can try to come out, but he doesnt. Whenever he DOES come out though, he will be scared of EVERYTHING, and will not go back in his cage unless I force him to step up on a perch and put him in. Now jes scared of the perch, and its even harder to put him in the cage. Today when I took him out, he just sat in one spot, crest erect, and did not move. Even when I tried to scratch him (he hates that and bites me) he didnt react. One day hell do great with training (he'll eat sunflower seeds and target), and the next day he'll be as scared as the first day I got him. I dont know what to do, and I might return him if he doesnt get used to us soon because I dont want him to live a life of fear of people, and I want him to have a good house to live in, which im afraid is not our house since hes scared of everyone. Ive had him for five days. He has not made any significant progress, so can you guys please help ASAP? Sorry for the long post but thank you guys so much.