Im trying to potty train my 2 yr old son. I have been for about 2 months. For the first week or so he did really well. We would (and still do) give him a little treat when he goes in the potty. we would let him pick the treat. But lately he wont use the potty anyore.. He will tell us he needs to go but when we get in the bathroom he wont even let us take his diaper off. He keeps saying no no no. he wont even sit on the potty with his diaper on.. What can I do? He was doing really good then all of a sudden stopped. Any advice?