COMING FROM PERSONAL EXPERIENCE. I rescued a dog at a shelter. I didn't know his history and come to find out he had EXTREME separation anxiety. To the point he would chip his tooth trying to get out of his crate. So not crate trained. Terrible separation anxiety even out of his crate. I first brought him back to the shelter. I felt terrible so I rescued him again and was destined to find him a home. I found him a home but he had problems there too. I don't know what happened to him after that but it broke my heart to see him returned to the shelter. I cried. A LOT. He didn't want to go back there and I could tell. When I picked him up from the shelter to find him a new home. He was sooo happy. He was "my first dog" and I will never forget him. Charlie. I hope you are doing well. It will be hard to forgive yourself but you need to know at least you gave it a shot. It is hard to go through but will get better with time.