You have received some great advice already Jon. Welcome to the forum. And even though you are not from the country I live in, I want to thank you for your service. It's so important to all of us to have a strong military!
I would agree that you need to get your PTSD addressed first and foremost. A clear mind will be an asset in navigating through the early part of your quit. You have quit before so you KNOW it's doable. Please do read all you can and watch as many of the Joel videos as you can too. Understanding this addiction and how it works is a critical component in not only quitting but staying quit long term.
You used the term "abstinence" earl on in your introduction. That is what you've been doing in earlier quits .... abstaining, not really quitting! You have not really taken smoking off the table as an option in your life. You still believe that smoking has and will do something good for you, which is not at all true when you really examine and understand what smoking is and how the addiction works in fooling us into believing it's our friend; our crutch in day to day life. That's where the education comes in Jon. Once you finally and truly understand just what smoking is, you will WANT to turn your back on this evil addiction. You will be happy to be rid of it