I had a similar experience with my first greyhound. He was young and I was single and worked everyday. He was very unhappy...and ultimately so was I...I returned him. It took about a month or two before I was ready to try again. This time I got a 4 year old actually he was almost 5. He was perfect in every way....took him about a week to ease into home life and was my best friend and most perfect dog. Well Not really..he was stubborn and a piece of work in some ways. But perfect for me and my life.