I got my cockatiel few days ago, hand feed one (that's what they told me)
I got him from a persons that growing them in his house not from a pet store. 
In the first two days I didn't even try to touch him, just changed his food and water and talked to him sometimes by sitting next to the cage. 
Some times I would have offer treats but he didn't take them. 
He's 2 months old. 
Yesterday (the 3rd day I have him) I put lettuce in my hand and just old it. He toke one bite and that's it. I left the cage open to see if he will go out, and he did. 
I let him be outside a little bit and then I try to per him, he was going around when I tried. Eventually I succeeded to old him. 
The first few pets he was trying to fly of (he's wings are clipped) so every time he tried I toke him back and just give him a nice pet, on that time he hasn't try to fly much but he still tried. 
I put him back in his cage.
Today I came back from work, try to old my hand inside to see if he will go on it and he didn't. I wanted to give him a nice shower, so I toke him out (most of the times he's on is food bowl so I take him out by taking the bowl out). 
After the shower I was trying to pet him again and he was kind of stressed... And today he didn't try to get out of his cage when I left the cage open. 
Yesterday when I pet him he's crest was all the way down on he's head. Today when I showered him it was half way down. 
I try to read what it means but I can't get the specific answer for it. 
Does I lost his trust by trying to make him calm and pet him?
What you recommend me to do from now on?
I don't know if it's good or not that I tried to pet him I just don't want him to lost his trust with me.