My husband and I had a separation agreement drafted in jul 09, now he is contesting the divorce?

My husband and I had a separation agreement drafted in jul 09, now he is contesting the divorce and wants the court to decide on the alimony and property separation, that was already clearly stated in the separation agreement. Can he win? Can the court change the terms of the notorized separation agreement? He is supposed to pay me $800/month, (which he has been doing since the agreement), and he keeps the house, everything in it etc, the other car... I really think it is about being mean and vindictive, as all i walked away with was one of the cars which i am making the payments on and the 800...So it saddens me to think....he wants that too?? I recently started working part time, but he wants to use the fact that I have a college degree and he doesn't. Do he have a leg to stand on? I found out that he has a top attorney now. It breaks my heart that I have to spend the money that I worked hard and saved on attorney fees now.