Will I loose custody of my kids if I voluntarily seek rehab?

I am a 36 year old male. I was recently granted full custody of my kids, despite the fact that I have been living with them and my mother. My ex who is the mother of my children is strung out on meth. Now I was introduced to meth from her around ten years ago. I’ve done it occasionally until the last few years. I’m starting to crave it more and my teeth are starting to show signs of meth mouth. I’ve kept my addiction hidden so far but I’m starting to want it all the time. I do not want the courts or my family to know I’m addicted to meth but I need help staying away from it. Is there an a ominous rehab? Or is this something that I’m going to have to explain to everyone?