I wonder if marble bone is just the doctor's personal description of osteoporosis?
On quitting cold turkey...I remember my dad used to smoke 4-5 packs a day, developed emphysema, then quit cold turkey when I was about 12. It was rough on him, but my mother helped us understand his jitteriness (is that a word?) and except for one really bad day, he never went back. Don't worry too much about being a "beyotch", you'll probably do better than you give yourself credit for.

Sounds like you've already come a long way! Congrats on that! You're certainly not a failure, you've undoubtedly worked very hard to cut back so much already. I've watched various family members struggle with this over the years. I watched my uncle die (literally) from emphysema. It's not pretty. I watched my aunt struggle back and forth with quitting for many years, before she conquered it. It's difficult, but keep trying, you'll get there!!!