(No affiliation).
Friends report there are no lasting urges, no mental blocks, no inner demons etc. etc.
reddit testimonials: https://www.reddit.com/r/stopsmoking/comments/odyv6/anyone_t...
It's extremely difficult to break a habit, but a lot less difficult to replace a habit.
Meaning if I'm able to examine the habit (usually a compulsion or mindless ritual to pass time or ease some anxiety) and understand the role it plays for me or benefit I think I get by continuing it, even if I could never imagine just stopping it completely, it's surprisingly easy to just do something else [intentionally do a specific different thing] upon the moment of urge to doing the bad thing. Eventually I just forget about the thing I did before, and my life becomes easier and simpler.
Because you mentioned books, if you happen to have one of the classic bad habits of modern life (smoking, drinking, eating), I'm always amazed how often people cite reading Allen Carr's "The Easy Way"series as the absolute only thing that somehow, magically, against all odds, worked for them. https://www.amazon.com/Allen-Carrs-Easy-Stop-Smoking/dp/0615...
There is one special book that I highly recommend . Allen Carrs - easy way to stop smoking. http://www.amazon.com/Allen-Carrs-Easy-Stop-Smoking/dp/06154...
It just works. But you need to be persistent with the decision.
The main idea behind book is that smoking is easy to quit. It is not addictive like alcohol, or other drugs, where withdrawal symptoms are intense. Quitting smoking is a big business like weight loss and there is a reason why they make it sound like a tough thing to do on your own.
As for relaxing, I haven't found a perfect replacement for cigarettes yet. I listen to music or read in my patio in the evening. Play video games. I also tried healthy stuff like running, working out, hot bath, or meditation. But nothing is perfect or I guess I am still not fully recovered from smoking.
[0] - https://www.amazon.com/Allen-Carrs-Easy-Stop-Smoking/dp/0615...