SUCCESS!!! after a few days and a few different tactics p-nut has successfully peed in the box twice! i'm so happy!
we went back to being more strict with his crate training and kept placing him in the box as soon as he came out, and i guess it finally just clicked. and i think he was just as excited as i was when he did it, haha. he came running over to me like a maniac.
i took some ideas from a few yt'ers, i took an oversized pad, folded it and placed it on top of a small layer of litter in the box. this way the box is weighted down enough for him but he doesn't have open access to the litter (which by the way, he has pretty much no interest in eating anymore, he kept putting some in his mouth and then spitting right out when he realized it wasn't food).
thank you sooo much for everyones ideas and tips! i realize he may still have some accidents but this is a huge step in the right direction