I know this may soung a little wierd,but try a bigger dog.Often times,bigger dogs our gentler.Our neighbor(an expierianced dog person)has a Jack Russel Terrier and a Golden Retriever.Or maby it's just that you spend soooo much time with him,your just being to good an owner!Also,did you get you puppy from aa breeder?As a puppy,did it have anough proper social interaction? You might want to think this through.