How can I get my rights to my daughter

I am assuming that because you are asking about a DNA test you did not sign an Affidavit of Paternity and were not listed on the child's birth certificate.  I am also assuming that you have no legal document as to support and custody.

You need to seek legal help in your area.  I believe that North Carolina allows you to file for a Petition for Legitimation which makes sure that you are given the same legal rights to your non-marital daughter as if you and her mother were married when she was born.  Once granted it is the first step to a custody and visitation order, which includes the financial support issue or child support.  This will prevent this roller coaster you seem to be on and set a fixed amount of support due as well as fixing your visitation with your daughter on a regular basis.  And it gives you rights that you can act on if your child's mother violates the order.  It also protects your daughter's rights to inherit from your estate should something happen to you.  Good luck.