I don't presume to know your particulars, so I'm not about to tell you whether you can or cannot afford your $1k per month child support. If you truly cannot, then here is something that might help you. Incorporate a business as an S-corp. (You can go to legalzoom.com and find the forms to file with your state). Then you will have a business, and all legitimate business expenses will be offset against your business income. Make sure you tell your client(s) to make any and all checks payable to your business name, and also issue any 1099's in the business name (although if you are incorporated, they technically do not have to). What this ultimately means is that only the NET income from your business will appear on your 1040, where your Gross Income is calculated.

If you do have an S-corp, then you will also have to file a separate tax return (1120s) for the business, and may need to pay an accountant a few $100 each year to do this for you, depending on how complex your business is. A judge may ask to see the 1120S, but only to ascertain that your business expenses are resonable. Mileage on your car for work, office rent, cell phone probably OK, but that $10,000 long weekend in Vegas, and the $400 golf outing with a "customer" who has been your best friend since 7th grade probably are not - you get the picture.