Kentucky took it out of your Federal taxes, which would indicate an increase at some point(seeing as how that's where mom lives), and for whatever reason, your employer never got the paperwork?
Maybe mom got a default judgment because she either couldn't find you, or said she couldn't find you.
If that's the case, and you haven't been hiding ( How could you be with the paycheck garnishment ), then you may have a case to abolish the interest and fees you owe.
But your first step is to call KY child support office.