I agree with my colleagues that statutorily, the judgment creditor is entitled to whatever your disposable income is. Now, you did (maybe do) have the option of filing an opposition to the Wage Garnishment (consult with an attorney or legal services) and explain to the judge an amount that would work for all parties.
The scenario for you is to contact the creditor's attorney and see if they'd be willing to enter into a settlement with more favorable terms to the both of you. Most attorneys will entertain settlements favorable to both parties, if it becomes unduly burdensome for the debtor to maintain payments.
Also, as a sidenote, in NJ, your wages can only be garnished by one judgment creditor at a time.
As for the child support, I know NJ has a good program in place for the monitoring and collection of payments, but I defer to my colleagues in that practice area.
This response is for informational purposes only and does not create or constitute an attorney-client relationship.
The judge has to weigh the creditor's right to get paid with your concerns. How long will it take to pay off the debt at 5% of your wages? 1.5% will take over three times as long. The federal protection is 30 x minimum wage; and they can take 25% of pay over 40 x minimum wage. Is 5% of your pay better than 25% of a 40 hour work week? It sounds like the judge has already given you a break by limiting it to 5%.
Unfortunately, the only way to get it to be less, would be with the consent of the judgment creditor.
In fact, the reduction technically was not legal for the judge but it is unlikely the collection lawyer would appeal. If they are entitled to garnish, then they are entitled to whatever the formula allows -- which is usually 10% of gross.
The reason is that the creditor has obtained a judgment. You are not entitled to say, I'll pay one creditor but not this judgment creditor.
The other alternative is to file for bankruptcy where you can get rid of certain debt and create a more orderly plan for paying those which are not discharged.
If you are that destitute, I suggest you contact Legal Services. If you do not qualify for legal services, I suggest you contact a member of the National Association of Consumer Advocates who handles bankruptcy or a member of the National Association of Consumer Bankruptcy Attorneys; their links are below.