Your addiction sounds exactly like mine. I'll do a half and be okay or I'll do 10 if I have the money, and essentially feel the same way. I've been unable to get past 2 full weeks in 5 years. I've tried tapering, subs, cold turkey, blah blah.
The truth is not what you want to hear, but the truth is: The taper will not work. Sooner or later, you have to pay the piper. That's one thing I've learned from my hundreds of relapses.