It’s not uncommon for co-parents to come in feeling like mediation is a “futile, last ditch effort”. The only way out of the suspicion, distrust and unskillfulness is through taking a small, calculated leap-of-faith, by engaging in 
mediation in good faith, acting with impeccability around agreements to build trust, and treating each other with increasing skillfulness/respect for the desired outcome. I’m imagining your desired outcome includes what’s best for your children, freedom from the conflict between you, as well as other issues yet to be discussed. Perhaps “avoiding court”.
As you know, demonstrating increasing skillfulness and building trust involves the ingredient of passing time … skills and trust build “over time”. THAT can be frustrating when you want and need an outcome “now”.
Conflict keeps people tied together. Moving out of conflict is a choice. Moving out of conflict often involves “letting go” of something for each person. Sometimes it’s letting go of the relationship, or perhaps a “principle”, or the desire to “change another”, or the notion that you’re the only one wronged or suffering. Once we put our heads together to solve the problems and follow through with commitment, conflict can diminish. Saying you’ll do something is not nearly as important as doing that something with consistency. So, you won’t know if co-parent mediation will help until new agreements are in place, new skills are built, and follow-through happens.