[designo]

First of all thank you for your question

How old is your dog? Is he a puppy
Also, you must put inside a crate and let him out 6 to 7 times a day to go play and toilet
Never go to him when he is barking, let hiim bark till he falls asleep

Dogs like being inside a closed area and dark, they feel safe so dont worry about switching off lights, its normal

Also, make sure you feed him outside the crate on time and let him get into a routine. It is not easy but you will see the results after a few weeks