Can i reduce my child support in louisiana?

hello here is my story, im 30 with 5 kids 9,8,7,5,3 year old my oldest one im paying support for my other four kids live with me and my wife at home,every time i go to court support increase ofcourse i dont have an attorney ,but i was informed that the court goes according to a chart and my bills or my expenses at home would not help ,how ever i make a bout 40k a year and 5400.00 a year for support thats is a bout 108.00 a week out my check,wich after a nother 120.00 for tax and 60.00 for insurance dosnt live me but 450.00 a week ,and i know if i get second job support will increase due to the chart , so is there any way i can get reduction ???