Help me save my son

For the past 4 years I have been alienated from my son. His mother refused to comply with visitation and even though I work full time, I haven't had any money to file contempt charges. About a month ago, I recieved a call from CPS/OCS saying they were revoking custody from his mother based on neglect. I was immediately awarded custody after a revocation hearing and have had him ever since. We enrolled him in school and he has thrived in the absence of his neglectful parent. She claimed to be homeschooling him, but when I had him tested at school, he tested at a 1st and 5th grade level, respectfully. HE IS 14 YEARS OLD. His mother is still collecting child support from me for him and interim spousal support. She has now (with the help of her enabling parents) filed motions requesting he be returned to her and his neglectful enviornment and that she recieve permanent alimony. I am a full time deputy on the streets as a police officer and can't fight my way out of this. I am asking for any help to go toward attorney and court costs to save my son. I don't want him to ever have to experience abuse or neglect again he has been through far too much for a kid his age. It is ashame that these cases can never be judged on the facts of what happened but instead on who has the better attorney. Please help me keep my son safe.