Child support calculation seems really off

Got the numbers back from our lawyer and the child support amount is way higher than I expected. I'm paying 35% of my gross income for one kid. My ex makes decent money but apparently that doesn't matter as much. I'm not trying to shortchange my son but I also can't afford my own place plus this. The mediator said this is standard but it doesn't feel standard to me. Anyone have experience fighting these numbers? Am I going to come across as a deadbeat if I push back on this?