Hi J.,
I have a 5 year old son whom I thought would NEVER be potty trained. He HATED his little potty! He did the same thing... he screamed, cried, kicked and refused to potty. One day I got so frustrated, I put him on the big potty, and held him there. Well, he went! I went out and got a ring that went over the big potty. My little potty converted into a step stool, so I used that next to the big potty. I bought a BLUES CLUES themed one, because my son LOVED Blue. I kept putting him on the big potty, and kind of closed the door so he would have his "privacy" - but while watching the whole time through the crack in the door. Turns out, he just hated that little potty, and wanted to be on the big one. We were off and rolling after that! I hope this helps!