All of my kids had "rest time" until they started school. Rest for both me and them :) I think it is time to consider not doing the nap-time nurse (he just wants to goof off anyways) and not laying with him at nap-time either. He is absolutely old enough to understand that mom shouldn't need to lay with him anymore. He screams because it works - if you are responding to the screaming, he will just keep doing it.
Make sure that his room is as dim as possible at nap time. After lunch, do the story and (if you really still want to nurse) don't do it in his bedroom. Do it in the living room on the chair. Offer him the breast once. If he isn't interested, then just skip it. Put him in bed and either shut the door or put up a gate so he cannot get out. Turn the music up in the living room so you aren't so focused on his screaming. Even if he screams the entire 1.5 hrs, let him. He is mad - not hurt and all you are doing by going in there is letting him know that when he gets mad, screaming will allow him to get his way. When nap time is up, calmly go in and get him. After a few days, he will either nap or at least lay quietly.
Good luck!