I have to tell you that this sounds just like the many, many, many times that I beat the myself up for being human. I'm learning to think of quitting smoking as a process filled with baby steps, we fall, we get back up, we fall again, we get back up...we get tripped up and we stumble forward. Eventually we learn a whole new way of getting around, and again, just like a little toddler, our world grows exponentially with each new horizon that we cross. You are going to do this! You will have to find your own way just like the rest of us and along the path you will learn a whole new way of viewing yourself - with compassion, forgiveness, respect and ultimately dignity - but none of these things is simply manifested overnight.
My husband and I gave each other permission to just go get a cigarette innumerable times and in fact, we finally realized that we needed to support one another, but that we needed to approach our quitting as individuals (if he slips it does not give me permission to slip and vice versa). So far so good. I have to tell you, I was getting pretty discouraged myself, in fact, i was beginning to think I would just stop trying and then this thing welled up in me and i realized that I've been in control all along the same way that you are...you are the one in charge, don't let yourself be fooled into thinking any differently! Even when you light up, you make a choice to, you are the one in control. You decide which way you want to see your life go, you manifest the vision of the you that you want to become and get started making it happen. It really is important not to have even one cigarette though, be honest with yourself about the way that they entice you back in and all it takes is one little puff. I realized that each time I went back to smoking I was really planning to do so in the back of my mind (I was planning to 'slip' and looking for my justification). I have to be on guard for this aspect of my personal process; be vigilant about monitoring the thoughts and visions I have of how my day will progress and notice when a cigarette starts to take shape. It's important to change your image of smoking, envision yourself smoking with an oxygen tank on, or full of IV tubes outside of a cancer ward choking down just one more cigarette before your next round of chemo. Another trick I use when I start lying to myself and telling my self that a smoke will lift my mood, or give me more energy, or make me more calm, is to rearrange the thinking into statements such as wow, a diagnosis of heart disease would probably put me in a pretty bad mood, or I bet people going through chemotherapy are inconceivable exhausted and pretty moody. Rearranging these thoughts helps me take an honest, objective look at the consequences of my smoking habit and not romanticize it.
Finally, if there's one really valuable thing I've learned it's that God loves us even when we smoke. My faith is very important to me and so I'm relying on finding God-given strength when my human weakness begins to wear me out. So last but certainly not least you have to be ready to take a huge leap of faith and see what sort of future you land in. Take care and I wish you all the very best.