Lucky 3 year old eating my kitchen help

We got lucky a few weeks ago from a rescue place he is great when your in the house with him or when walking no problems.The wife was off for a week when we first got him and we tried create training locked him in when the wife went out for short while and when returning he had damaged the bars and the door so we bought a stronger create which we did the same process again with the same results complete destroyed the create.Then refused to do into the create and thinking that it would cause the dog stress we moved him into the kitchen.He had his bed and toys and bones with him radio left on something of the wifes in the bed so he could smell it to help him keep carm and plug in things which are meant to help him keep carm.The wife went out again and on return he had chewed the kitchen door and destroyed the cat flap and managed to get himself into the side entrance.We boarded up the kitchen door and tried again he then destroyed the door and the door frame which lead into the living room and bent the child gate which we had put up to keep him in the kitchen.We really need help as this dog when you are in the house with him is so nice and gently but we can not leave him alone in the house and dont want to lock in the garden when out as he will destroy the fence and could damage next doors property

How often do you walk him?? And what do you feed him? I have seen often these 2 questions can be the source of a lot of these problems.

Sounds like seperation anixiety. Make sure to exercise him before you have to leave. Also try leaving multiple times during the day and incresing the time you are gone slowly. Start off with 5 minutes and build up gradually

Hi we walk him twice a day, he is fed pets at home light and sensitive dry food (everything else gives him an upset stomach). We have tried building up to leaving him, we did this for the first two weeks of having him, he still hates being alone.