[US] Lying ex, mediation, how to deal

Ex has chronically given up his parenting time for the last 3 years. Taking it sporadically and then demanding "make up time" any time some extra fun thing happens during my parenting time. I finally put my foot down only to have him request a parenting time mediator through the court.

We now are suppose to have 1 joint meeting (zoom) and each have an individual meeting with the mediator.

I suspect my ex will be spinning all sorts of stories about me "withholding" the kids and I just can't deal with these constant lies anymore. Now I have to explain the situation all. over. again.to another individual at a rate of $500/hour.

Now I do have extensive documentation of every missed visit etc. Do I just forward that whole spread sheet to the mediator up front? How do I even begin to sum up the last 3 years of failed coparenting and what has 'brought us to this point'?

I have nothing to say to my ex. I don't even want to look at him at this point. I don't want to go round and round with him again on any of this. We've been separated since 2018!! He is unresponsive to any messages I send through the app yet cries 'court!!' every time I won't give in to his demands.

Send help.