What is your income? Who pays for the children's health care? Who pays for the uncovered health care expenses? Do your children have any special health needs? Do you have day care expenses for your children? Do you have any extraordinary educational expenses (i.e. do they see a tutor)? What activities are the children involved in (sports, ballet, dance, camps,etc...)? What are the expenses associated with these activities?
In Georgia, child support is calculated based on the child support guidelines, which uses a shared income model. I suggest that you think about the questions above, gather the information you need to answer the questions, and then contact an attorney for a free consultation to determine an approximation of the child support that you should be getting.
An attorney could literally save you thousands of dollars by doing your calculation properly.