I regret buying a bird
Why don't you want the bird anymore?
I just realized what kind of commitment that was.
Well, it's your pet now so you need to take care of it.  Otherwise, I'd suggest taking it back to the shop!
I can't take it back. It's so difficult to take a pet back.
Then I suggest you adjust your attitude towards your bird, it's important to take care of your pets the best you can.