Here’s my advice on how to really and actually quit: make the decision to quit, and keep making that decision. Every time you feel yourself thinking “just one more…” remake that decision to quit. This was the only way I was successful. Keep making that decision and keep reminding yourself about your decision. You can do it.
The fact that I am not the only one thinking this is encouraging. The fact that I had to scroll this far to see such a correct comment is very discouraging and worrisome.