Did I make a mistake?

My last dog passed away 10 years ago. I had him for 14 years. My heart was yearning for a new best friend, and when my daughter asked for a puppy I knew it was time. Picked out a cute little blue merle australian shepherd, told the breeder it was for my daughter and I. He told me he would bring the other puppies to see if we bond with one of the others just in case. When we showed up the puppy I picked wasnt there. I'm not good with confrontation, and my daughter loved this black tri, so we ended leaving with him. Just figured the other puppy wasn't meant to be. Now it's been a week, and I'm regretting get him. My daughter loves him, he is a cutie, but I don't want the responsibility of taking care of him. I was all for it with the other puppy, but I feel like I got tricked and my heart just doesn't seem to want this puppy. I feel so bad about it. Did I make a mistake in getting this little guy? Think it's just normal puppy blues and It will get better?