Oh I so feel your pain. My Mylee is exactly like this. I don't have any good answers for you because we have Moka who is a babysitter dog. Without Moka, without a doubt our Mylee would be destructive. We've tried it. Have you tried a crate? I know it's small but for the amount of time you are gone, he should be ok in a crate and shouldn't be able to hurt himself or be destructive. Maybe it will help him feel safe and secure with a smaller more confined space and with time he'll be ok to be out while you are gone.
__________________ Shelly and the girls  Moka Mylee |