You should think of the quote “if there's a will, there's a way”. I think you haven't done everything or anything, because if you've everything as you've said you already find a way to quit smoking.
I know this is going to sound trite, but you CAN stop smoking if you truly WANT to.
I used to feel just like you, do a Rip Van Winkle and sleep through the cravings and withdrawals. I can't tell you how many times I gave into that crave just 15 minutes after I said that this was my last one! That's because I really didn't want to quit. After smoking for 40 years and using an inhaler for the last 5 of my smoking years, I decided that it was time. My doctor actually handed me a RX for Chantix and a coupon and told me to try it. I held onto the script for a month or so and then filled it. Thankfully I didn't have any serious reactions and within 6 weeks I was an ex-smoker. It wasn't easy and I worked at it, but I was finally able to take my life back.
This forum and the people on it were a large part of my quit. Support is so important! Also, whyquit.com is a very powerful website that helps you to understand your addiction and what you can do to help yourself. It supports a cold turkey quit but you don't have to quit that way in order to access the articles there.
Did you know that the physical withdrawal lasts 72 hours? Anyone can quit for 72 hours if they truly want to and after the 72 hours your physical craves will be manageable. What you will have to deal with then is the emotional addiction. That's when those articles at whyquit.com will truly help.
Have you decided what method you are going to use?
We have all been there and no, it's not easy, but it is do-able, I promise you that : )
We are all going to be there for you, whenever you need us to support you or yell at ; )