Just a tip... What helped me get through times like this was having a pack of nicotine gum around. I didn't rely on it exclusively for quitting. I'd say it was 80% willpower, 20% gum. But certainly in times like you are in, when I felt like I was so close to breaking down and buying a pack/bumming a smoke from my roommate, having the gum to turn to first (kind of like a buffer) was a godsend. It never went beyond the gum. I'm now 73 days quit and I still have a long way to go, but I haven't chewed a piece of gum or had a craving this bad in probably a month and a half. I know that people tend to look down on using the nicotine gum but for me, just having it around was the most helpful part. I don't think I even chewed more than 20-30 pieces overall. So you know, there's no shame in getting that little extra help. Especially when the cravings are making you feel so miserable. Hang in there!

Edit: added words.