I just to rip his lying mouth off!!!! Custody rant***

So, going through a custody modification for our child. I'm being civil as to the only reason I filed a modification is because child will be starting school soon and would like him to be in one home throughout the week for school instead of our spilt 50/50 week. We don't live in the same district and he has no other children except his step daughter, so I also want our son to be able to attend and bond with his other 2 siblings since they are all really close in age. (I have remarried and have two children with current husband) there are some issues where I feel step mom crosses the line (takes son to doctors without my knowledge and makes medical decisions without my consent) we have both joint legal and physical so everything is supposed to be agreed apon. Other than that we mind our own business always there for exchanges to ensure he always gets his time with the other parent because that's what's important. No fuss no mess just be civil. So I file for this modification to go in affect when school starts, he counters slandering me with all these lies!! Wants child support (actually mentioned it 4 times in his motion) says I've moved several times, says I put our son on medication without his knowledge (interesting bc my counter was that I've been alienated from medical choices) blah blah blah. I can't even believe one you would lie like that and two since when is raising our child all about your pocket book (he has never paid support I never wanted him too, felt we should be capable to take care of him as needed between us) the only thing he was ever ordered to do was provide insurance which he never had until recently. I'm so pissed I can't even stand it. I just wanna blow up on him.