If you are not pro-active with your quit it will get away from you.
This site says it takes 8-11 "tries" to quit.
It only takes one committed attempt. Whether that's number one or number 11 is up to you.
It surely must be discouraging to do it over and over.
It's in your hands as to how you prepare and where you get your mind to before quitting as to whether you will succeed.
GNU