Well done to Bunfags and everyone else who is giving up - it's one of the hardest things you can do. But don't give in, just keep at it...
I thought I'd tell you how I did it (with a bit of background) and hope that in some small way it will help.
I started smoking when I was about 11, and I smoked for 25 years, very heavily for most of that. Over the years I tried everything to give up - patches, gum, accupuncture, hypnosis, will power - nothing worked. (I've heard it's a worse addiction than heroin and cocaine!) A health scare made me decide that I had to give up once and for all or I'd be in big trouble. And I decided that I would just use willpower otherwise I'd be addicted to whatever I was using instead. So I gave myself two months, gradually cut down to 7 a day (from 20-30), and then just stopped. It's one of the hardest things I've ever had to do; I had all the same things that everyone else has mentioned, bad skin, colds, chest infections etc, and I did gain about a stone in weight. I knew that if I gave in and had even one smoke, I'd be right back to the beginning and have to go through it all again, and I didn't think I could bear to do that.
Someone mentioned taking a deep breath when you're having a craving because oxygen gives you a natural high - that's right, it does, and just remember that a craving only lasts a couple of minutes - do anything to get through it. Take deep breaths, jump, skip, sing - anything that helps you get through those couple of minutes.
One thing that I did that helped me more than anything is really stupid, and I know it's psychological, but it worked for me. I told myself that I wasn't giving up smoking, and that I was going to smoke again, but not until I am 70 years old. Because every other time I tried to give up and told myself that that was my last cigarette ever, I just panicked and didn't know how I would cope, but knowing that in the future, if I wanted to have one then I could, was liberating.
Four years on and I'm so glad that I stuck at it and I'm really proud of myself - I never thought I'd do it. I do still fancy a smoke now and again but I'll just have to hang on til I'm 70!
Anyway, I'm sorry to go on. Good luck, hang in there, you'll get over this and be glad you did. Everyone is rooting for you.