I think if you really want to reduce your overall size, seems like the only way would be to decrease muscle mass. I know we all gain muscle at different rates, and have different maximum (natural) muscle size. I sort of worry about getting too big, too, because I seem to put on muscle very easily. So I imagine if your goal is to become smaller in size, you probably have to stop lifting so heavy and just do less lifting overall. I imagine you will lose strength, and maybe be less happy, since it seems like you really enjoy your workouts. It's all about compromises, so you just need to figure out which of the variables is most important to you. Sucks that sometimes you can't have it all, but I agree with Kuno in that I am sure your body looks absolutely amazing as is!
Everything in moderation, including moderation.