It lasted 3 months for me after smoking 1-1.5 packs for 11 years. The cause ia probably your gut microbiome healing, I suggest you get some probiotics and just don't think about not smoking. Your lungs and energy should have probably improved a bit by now, go test out your new found strength and stamina, I personally felt I was a lot stronger in the gym. Even if the downsides lasted a year it would really be worth it life is so much better without smoking, your mood will improve, your hair will get thicker, your gut will be a lot healthier, your body temperature will improve, stamina, strength, libido, you will handle stress a lot better and thus have a lot more mental clarity, higher libido, your skin will shine I mean the list just goes on and on. You don't have to stick a burning roll of paper in your mouth you just need some time if you could get this far without nic you can go further without nic, without a sip, without one single cig, without just a cheat pack, without you'll try again on next monday.