You likely didn't make the decision to end your marriage because your spouse is such an amazing person. Instead, there are probably issues present that make it difficult for you to remain in a relationship with that person. Unfortunately, a difficult spouse is almost certain to make life difficult for you during the divorce.
Trying to protect your interests during this type of situation can be complicated. You might not know what to expect from them at any given point. This makes it hard to figure out what you need to do.
Many people use mediation to come to the terms of the divorce. If you are doing this with a disagreeable ex, you have to remain focused. They might use their crankiness to get their way, but you can't let that happen unless it is in your best interests.
Determining where to draw your line for this process can be hard. You do have to be willing to compromise, but you don't have to give your ex their way on every matter. Instead, decide what you are going to fight for and focus on those aspects of the negotiation.
Divorce is a tense time for both sides. Instead of bringing up the past when you are working with your ex, think about the future. You can't change what happened before, but you can control what happens from here. By keeping the focus on the matters at hand, you might be able to resolve the divorce faster.
The emotional impacts of dealing with a combative ex can wear on you. It may behoove you to speak to a therapist who can help you to come up with coping mechanisms for handling everything. Remember, you can't absorb your ex's problems. You can only do what's best for you.