My 1.5 year old year old male shih-tzu is destroying my house HELP!?

We have had our dog a little over a year now. He is a 1.5 year old male shih-tzu who is not yet fixed. I love my dog but he has been a pain since we got him. We've tried so much to correct his bad behaviour but nothing works. His latest offence is scratching at the trim, walls and door when we leave. we are never gone for long either. Since we've got him we have always put him in our bathroom ( it's big ) and he has his bed, food, water, toys and now he has turned to destroying it. He knocks his food bowl over, dumps out his water and hides his bowls, scratches and chews the door, wall and trim and will rip up anything left on the floor. While he is having his scratching fit he drools? We arnt sure but he gets himself soaking, soaking wet. His whole face, chest and paws are soaked. So we tried crating him in a different room and he moved the crate over to the wall and destroyed the wall. He was covered in drywall and waste full of paste from the drywall mixing with his drool. While he is crated he jumps and scratches all over it and barks constantly. We leave him with toys and a bed in his crate and he still does it. Someone please help! If we cant get him under control who knows what will happen. I am afraid he will hurt himself.