What if the original decree for divorce differs significantly from the final decree?

I filed for divorce in Texas in February. My final divorce date is Sept 15th. When I filled out the original petition for divorce, I filled out that me and my soon to be ex husband would be joint managing conservators of our children (both under the age of 3) and that he would have standard visitation. He signed the respondant's original answer, agreeing to the terms. Due to recent events, my soon to be ex husband has landed himself in the mental institution (4th time I know of, total) and sent threatening messages to me. I now wish to fill out the final decree for divorce as me being the sole conservator OR at least him having supervised visitation. My question: since the final decree differs in terms so significantly than the original decree, will the judge accept it if I provide proof of mental instability on his part? I just don't want to fill out all the paperwork incorrectly and then not get divorced.