Child support isn't really a negotiable matter. People who are ordered to pay it must comply with the order or they can face legal woes. The thing that is difficult about child support is that you have to pay it no matter what you have going on with your life. If you are in a position where you can't make the payments, you can't just avoid the matter without facing consequences.
You have the option of seeking a modification for your payments as long as you have circumstances that meet specific requirements. This might be a job loss or demotion. You should try to continue to make the payments as best as you can while your case is moving through the court system. This will help you to remain as current as possible.
If you are in arrears, you need to make plans to catch up as soon as you can. There are penalties that you might face that can cost you even more to get current. But when you have a modification pending, the court can't seek repayment for arrearages beyond the date of the initial child support modification petition.
Another consideration for many parents is their desire to provide support for their children as much as is possible. It is understandable that you need money to live on as well, so don't think that you are doing the wrong thing by seeking a modification when you really need one. You can always find other ways to provide support your children until you can get on solid financial footing once again.