Do I have to pay child support after my child turns 18?

My ex-wife is seeking to have a court order me to pay child support for my daughter even after she turns 18, which is in 6 months. I’ve paid regular child support, on time every month, since the divorce ten years ago. I’m ready to be done paying the support. The mother is telling me that I’m obligated to continue paying because our daughter has certain learning disabilities and special needs. I love my daughter and will always help her financially when she needs it but I don’t want to be ordered to continue to pay support to her mother rather than just directly helping her. Can I be required to pay the support beyond age 18?