Not much you can do..
Kevin,
Unfortunately there is not much you can do about it.
This is how the system works. Once you have bad information on your file, it’s there, impacting your credit score. It will remain there for 7 more years, although as time passes it will have a lesser effect on your credit score.
Even if you pay off retroactively – it will still be there.
BTW, from a legal point of view – you had no right to stop these payments.
What you CAN do is to first pay what you owe in child support. Then, contact the Child Support Services (if you pay to them) and ask them to update the information with the credit bureaus.
That will not take off the bad remark but will add another notation that the account has been reopened, etc.
Although it won’t do much to raise your credit score, most lenders actually do acknowledge it if you at least try and repay what you owes on child support.