Anyone voluntarily went to drug rehab?

Ok...I have to be quick cuz my boyfriend is abusive. I had to create a new account so that I could post this. Anyhow, I'm addicted to meth severely! Daily use, probably 10 foils a day. No exaggeration. I WANT to quit and go to rehab. I dont have a way to research this without him finding out. I want out of this life. How long do they keep you? Whats it like? Where Should I go? Can I smoke? (cigarettes). I'm from Michigan. Please if someone could do the research for me and post it, I would appreciate it very much!! I also ist in manufacturing it at my home so I don't want the cops to find out anything before I get help and get this **** out of my life for good........