Once I receive a letter of emancipation from the child support office, Am I still financially obligated to pay.

You are required to pay child support to the custodial parent until a child reaches the age of 18, however, if that child is still enrolled in high school then child support continues until the child graduates high school, or reaches the age of 19 - whichever occurs first. So you must determine if the child support was terminated too soon - if your child was 18 years old but still in high school then support should not have been terminated at 18. But if your child has graduated high school and reached the age of 18 then the Office of Child Support Enforcement (OCSE) was correct to terminate child support --and may have received wrong information as to the child's status.