Re college child support
, The law of the jurisdiction in which the first child support order in a case is made, controls whether or not a parent is obligated to pay college/adult child support. Texas law does not provide for college child support, therefore, absent the other parent's consent to pay such support as part of your marital settlement
agreement, you cannot legally force him to pay.
Re changing the settlement agreement after final judgment, based upon a claim that your ex signed the agreement under coercion or undue influence, the chances of relief from judgment is nil. No way, no how. Not gonna happen.
The reason is simple: If courts routinely permitted such relief, everyone
would come back to court looking for "another bite at the apple," whenever they didn't like the outcome at some future date -- and no one's divorce would ever be final.
So, don't worry about this, because it's a hollow threat.
Hope this helps.