DOES THE NEW TAX LAW AFFECT MY CHILD SUPPORT?

The answer is maybe.  Essentially the new tax law, which took effect January 1, 2018, eliminates the child dependent exemption.  However, the standard deduction has been increased significantly, so those two may cancel each other out.  For more detailed advice regarding tax matters, you should talk to a tax expert such as a Certified Public Accountant, and to an experienced family attorney.