21 month old behavior?

I have a 21 month old son, and am not sure what to do. Yesterday he got into the toilet paper and pulled it all off the roll I smacked his hand told him no. Then he smacked me back so again I told him no and made him sit on the couch but he did not want to sit there. He threw a fit and kept trying to get down...I bear hugged him and held him in my lap then he bit me leaving his whole mouth imprinted on my hand...any suggestions? I might add that here lately he has been throwing a lot more fits like he has never done before.