You are allowing this child to rule your house. You had better get a hold of this.
No more TV after dinner, period. He shouldn't be seeing much TV anyway - there is so much for a child to learn that doesn't include TV. It appears that one of the things he needs to learn is discipline and limits.
When he is at home with you, you need a real schedule. Bedtime should be the same time every night. Getting up should be the same time every morning. What time do you try to get him to bed? If you are trying for 7:00 pm, that's probably too early. 8:00 or 8:30 with a wakeup time of 6:30 is appropriate. (Depends a bit on what time you have to leave the house.) Headstart has a real schedule - you need one too. If he has tantrums, put him in his room and don't pay any attention to his tantrums. When he is done, have a talk with him about how tantrums do nothing but lose him what he wants.
At night time, have quiet time after dinner. At bedtime, have a short and simple routine. Perhaps a bedtime CD would help.
I would sit in his room with the light off after book reading, with your back away from him. Everytime he gets out of the bed, put him back in it and do NOT talk to him. It might take hours the first night. Keep up with it for as many nights as it takes for him to finally get in his head that nothing he does will change having to be in that bed. It will get boring and eventually he will give in and go to sleep.
In a few weeks, you probably won't have to sit in his room anymore, or maybe only for a few minutes. Remember, keep night time calm and quiet. He may want to have a "burst" of energy. Don't let him. Keeping him corralled in his room with quiet activities will help this. No fussing, no yelling. Quiet music, quiet talk.
Good luck, E..
Dawn