Not his fault, your fault. You need to shove your nose in the recliner and yell at yourself, "NO!" several times, and for good measure, take the ripped up paper towels and slap yourself upside the head with them.
You are going from no freedom, no chance to get into trouble, no chance to do anything wrong to handing him the keys to the house and car and giving him the day to do his worst. You set him up. Really. He chews because he is bored, maybe lonely for you, and because it is a self-rewarding behavior.
The best thing to do now is to give him some freedom for short periods of time. The rest of the time, you teach him what he can have and what he can't have. Puppy proof a single room and install a good extra-tall baby gate in the door, and leave him in there during the day, and when you get home, ignore him for a few minutes. Keep comings and goings very low key. WAIT if possible until he quiets down, and then come in and take him out to do his business, a bit of training, etc, and the rest of the evening in with you learning what he can do.
Also before going in the morning, a good long walk and maybe a good game of fetch, so that he is good and tired out before you leave him in his place.
Tractor supply sells a sturdy 10'x5' kennel in panels, that you can set up in a basement or garage. Your dog will be safe there.
What is scary about just giving him the run of the house, is that there are thing in our houses that are dangerous for puppies to eat, stuffing, stuff off of counters, stuff in walls, cleaning stuff, blinds, cords, and so much more. Puppy proof an area, or make him a day-time area where he can have a safe, raw, bone, or a hard rubber toy or two, and a bucket of water, and maybe a cot. Then when you come home, the only thing he can possibly destroy is what is in his area.
And no one gets punished, and no one feels guilty about it.
Bear Cub, Hepsi-Pepsi
Cujo2, Karma Chameleon
Ramona the Pest, Kojak -- who loves you baby?
Tiny Tinnie, Susie's Uzzi, Kaiah -- The Baby Monster.