When deep breaths doesn't cut it

I am aware that a little reverting is a given when a three-year-old is introduced to a new baby, but this has become ridiculous. The screaming and the defiance is to a level in which husband and I can't reach. We tried sending him to his room, being calm and explaining why it's not good behavoir, spanking. After explaining and setting the punishment, like taking away TV prevliages, he asks to watch it over and over and over again. And we tell him over and over and over again that he was bad so he can't. It's like talking to a broken record and finally I just give in. He refuses to go to bed, and screams and hollers. He wakes up in the middle of the night crying, when I go in there to see what is wrong, he doesn't tell me so I leave and that starts more screaming and hollering. I am soo lucky that the new baby can sleep through all of this ruckus. I'm just at my ropes end and don't know how to handle this.