It's hard to smoke period, but when you're stressed about it like you are now, it makes it even harder.
My advice is to watch the videos on the Become An Ex Plan, for some reason just knowing the physical reasons for wanting the cigarettes made it easier. Kind of like knowing that it's a short in the wiring that's causing your oil light to come on in your car rather than an actual need for oil, lol
I quit cold turkey two days ago and it's been really hard but what has helped me is fast forwarding in my mind past that one cigarette and imagining how I will feel.
This is what the image is like every time...I'm smelly, my throat is burning, my chest is aching, I'm coughing and now I've set myself up to want another one even more.
Also, I've come to view and treat the addiction like I would my children. If they were asking me for something that would hurt them..."Mom can we go play on the roof?" I would tell them "NO!" no matter how many times they asked. So maybe that will help.
Also, I noticed before when I tried to quit that usually when I did slip and have that cigarette it's because I rushed it into my mouth before thinking about it. So maybe if you make yourself really think about it, argue with your conscience about why having that cigarette is a good idea...or have a nonsmoker play that part and try to convince them and watch their face. The longer you delay, the better and you show yourself that it may be an addiction but you don't have to play, you can decide to wait...forever!
Good luck and we're here to support you!