Is he in school? He should be by this point . . . and if so, how is he doing there? If his behavior is so bad, I am sure they are addressing it. They would do an evaluation to see if there is any reason for the behavior such as a developmental delay or a psychological issue or if his speech is delayed, etc. So, where are you /he with all of that?
Also, just a side note----- they don't medicate kids for being bad. He would have to have a documented, diagnosed medical condition. There is a process to follow with that and it is important. If he is misdiagnosed, he will then have the same behavior as well as side effects from the med.
What does your son do right? Some kids will seek negative attention in order to get any attention---- and they can go to great lengths. He may also have something going on with regards to his processing (nervous system). Some kids touch often because they are not aware of others space or they need to touch in order to process. Some kids have auditory issues in which you think they aren't listening but in actuality they just aren't processing what you are saying.
So, there could be things going on beyond his control. Also, how do you discipline?
first of all, I'm sorry things are so bad, it must be terrible and you must feel so out of control. Is he in a school situation? How does he do there?
I think it would not be a bad idea to get him evaluated to make sure he is okay and it's not behavioral or mental or both. YOu just never know and at this age you want to be careful.
HOw long has he been like this?