I agree with Sveets in terms of starting out small. Don't just jump to 12mg of subs at first.
Once you've started experiencing some decent w/d's, I'd start with more like 2mg under the tongue, wait about an hour and see if you need another 2mg. I wouldn't go above 8mg in the first day unless it's really unbearable.
Spread em out as best as you can. Add some 5-HTP from a GNC, low doses of benzos if you've got them, clonidine (again if you have it), Valerian Root, immodium, and vitamins. Drink plenty of fluids, eat as soon as you feel up for it, and as soon as you feel up for it try to get out and take a walk.
Masterbation is definitely another +, but it takes longer for some than others for the testosterone to be back to make that possible.
Best of luck to you. I'm going in for my second doc appt on Thursday to get myself on an official sub program (from Heroin, but my previous addiction was Oxy a couple years back). If all else fails don't be afraid to give outpatient (or inpatient) treatment a shot.