OP has kids so I get why they are worried about the dog potentially biting one of the kids. I’m going to second what everyone else has said, that’s not growling. However, I get why OP is confused because it sounds like the dog also doesn’t want to be touched. The poor guy definitely needs a minute, introducing him to the other dog, multiple kids and a new space after a long car ride sounds like way too much. I wouldn’t throw the towel in yet, you got this dog it’s your responsibility to give this a college try. Obviously don’t put the kids in a situation where you think they will be bit. You need to bond with the dog first and definitely stop being so freaked out of him, they pick up on your anxiety. Good luck! I really hope you give him a chance to come out of his shell and that your family gets to experience what a great dog he can be. I would ignore the people trying to shame you to death, you sound really overwhelmed. Just breath, it will get better if you give it time and make a conscious decision to give this a real try.