Hi N.,
wow, you have the patience of a saint!
I think if you change a tactic it might help. I know time out is popular but I am not a fan , because it separates the child from the one he needs support from the most during those training moments. In an empty room he is not being reflected or guided, he just knows your gone, and having the security of mother being there is his number one need. I think the separation anxiety is what is making him go apoplectic. I really believe young children at that age don't logically sit there and "think" about what they did and 'should' do next time. That seems a little advanced. Operant conditioning is the key word here, and works much better at that age and for infractions, like hitting for example. Operant conditioning is an immediate, consistent painful feeling each time the offending action happens, causing them to deter because neurons respond and encode for conditional stimuli. An example is a slap on the hand and a stern NO, looking directly into his eyes, each time he hits. Do not smile, or speak in a low sweet calm voice. you will be sending him a mixed message. 90% of our communication with other humans is done through facial features and tone of voice, only 10% with words! You need a stern No and a serious look. Then when he starts crying after his reprimand, you hug him, showing him love and telling him you understand that this was not pleasant for him,(or you) but you will not allow him to hit and you will always be here for him while he works through this behavior. This way you comfort him in his time of need and training, rather than pull your love away with solitary confinement.
Even animal moms such as dogs train thier offspring with operant conditioning...a stern nip on the neck when the pup is doing wrong.
The key is consistency. Condition for every time the infraction occurs. If an all out fit with kicking and screaming ensues after a punishment - I would NOT pick him up or try to console, because you are conditioning negative behavior with a positive response. That will ingrain it all the more. Walk away, leaving the child on the floor kicking, and do something else. Tell him it hurts your ears when he screams in them, you will not allow him to hurt your ears, and when he calms down you will be glad to come to him and spend time.
You could try to give him more naps....maybe two naps a day at that age. Lots of Magnesium and less calcium has been shown to decrease aggression and anger in children.
Good luck and hang in there. It will all work out.
Parenting is a lot of trial and error, just do your best and give the rest to God.
Gail