Why won't he sleep?

I have been through this several times now with Ivan, so why is it still so upsetting?

Ivan is still napping for an hour to an hour and half every day. I put him in his bed and tell him that he does not have to go to sleep, but that he needs to have some quiet time. He goes to sleep almost every day. At bedtime however, he stays awake until J and I go to bed and sometimes long after. Like last night for instance...he was wide awake at midnight. I finally went in there and yelled at him that he needed to be quiet and go to sleep. Not the way I really want to end our day. Then this morning he did not want to get up and it took me 10 minutes or more to get him out of bed. He had preschool this morning so it was imperative that he get up and get going in a timely manner.

He napped again this afternoon and I am planning on putting him to bed early because he is a basket-case from being so tired. I am at my wits end about this and I just don't know what to do to get him to sleep.

I will admit that there is a part of me that thinks getting rid of nap time is the answer but then there is a part of me that needs for him to nap, so that I get a midday break. Perhaps the answer is to give him a real quiet time and not do it in his bed. I'm just not quite sure how to make that happen. This parenting thing is tough and I just hope that I am on the right track.