I forget what it's called, but the military offers an allowance for child support. It's tax-free, like a housing allowance. You need to look in to that. Depending upon your rank and/or pay grade, the child support allowance may be all you hafta pay.
File a "MOTION TO MODIFY" immediately - the sooner, the better. This is called "substantial change in circumstances" since the last order was written and is grounds to modify your child support order. You can do this yourself (pro se), and get an attorney later, if need be. Better still, start by filing a modification thru Support Services. They will handle this administratively and/or do a confrence call over the phone if necessary.
Remember, the family court system doesn't take kindly to reductions in child support. So you can expect them to drag their feet. This will take a while, like a year or more. So, you've gotta dig in for the long haul.
Everyone is entitled to my opinion. - Maxine™