You said you had quit for 6 years but then made the decision to start again because you missed it. Obviously it wasn’t the nicotine that brought you back to smoking, but something else.
You would do well to figure out what that is, because it stems from that part of you that wants to be a smoker. Your doubt when you light up shows you are in conflict with some part of yourself.
If you really want to quit, link up with a support group to help you past the craving hurdles. If you don’t, then start thinking of yourself as a long-term smoker and enjoy each cigarette.
I’ve chosen the latter and now I love being a smoker.