Hello! Were you talking about someone else? Because the use of "yo" at the end could happen in a situation like the folllowing: you want to do something with someone and this person doesn't want. You get angry, and after a while, he/she says 'OK, I will do it'. But then, you don't feel like doing it any more, so you say something like "now it's me who doesn't want to do it". This it would be something like "Ahora soy yo la que no quiere hacerlo" or just "ahora no quiero yo" (with "yo" at the end).