So, today the Lord revealed to me a little more meaning to my dream. I have allowed Satan to stop me from getting the rest that Jesus wants me to have. The sleeping baby inside the house represents this rest, and I was unable to get in because I was too afraid and was running from Satan (the dog). I had the key in my hand but didn't use it. The key represents faith. In the end I saw that Satan couldn't touch me because I am protected by God for being obedient to his voice.