hi 247dlwear
i can only respond by the little bit i have picked up along the way. have you been to therapy to discuss this to help you understand? when something is confusing to us, it is helpful to go talk it out with a professional to help sort thru that confusion so we are comfortable with our decisions. this is where i would go with it from the information you presented. i am not a therapist, have limited knowledge, but this is what came to me. it is something to consider or totally laugh at and throw out the window....lol. potty training is about control. forcing kids to potty train too early can be traumatic. it is about them learning how to control their bodies. potty training at 4 1/2 is relatively late so it seems as if there may have been a struggle for control with the caregiver. so i would piece together that the fetish may somehow be a subconscious attempt at regaining control of life. that there was powerlessness felt as a child and now as an adult able to do as one wishes so it is manifesting as this fetish because as a child the choice to leave the security of diapers was taken away before the child was ready.
I hope that makes some sense. welcome to psych central. you will find we have several forums where you can post about your concerns and receive feedback from other members. you will get a lot of support here. again, welcome