First, "opting out" of FOC services does not relieve a parent of the obligation to pay child support, it just means that the FOC does not facilitate the payments or provide immediate enforcement assistance upon nonpayment.
Second, even though child support payments are made payable to a parent, they are for the benefit of the child. Therefore, the fact that you failed to enforce any child support payments for the last 5 1/2 years does not relieve you of the obligation to pay support for the child now that she is living with the other parent. The right to child support is the right of the child.
Finally, you cannot just send a letter to the judge. The judge is not allowed to have any ex parte communications with either party (except in very limited circumstances that do not apply to your situation). All communication to the judge must be in the presence of the other party or in the form of a pleading filed with the court and served on the other party.
As you can see, not having a lawyer the first time around has caused you a lot of problems. I highly recommend you consult a local attorney.
DISCLAIMER: This answer is provided as general information, which may not be appropriate for the specific facts of your particular situation. No attorney-client relationship has been established based on this limited communication. You are advised to consult with an attorney in your jurisdiction before taking any action or inaction that may affect your legal rights. www.hecklerlawoffice.com
Your Judge will not read or review an ex parte communication (a communication from one party without a record). You will need to file a proper motion to reinstate FOC services as is your right and for an appropriate review of child support since much may have changed since 1999.
This is a general response to an inquiry and is not intended to create a lawyer-client relationship in any manner.