I smoked for 4 years and quit on 17th January 2020. Have been smoke free since (just realized I finished a full year this Sunday).

First 4 weeks, I had a runny nose, dry cough and persistent cold. The next 2-4 weeks I had the same symptoms with a phelgmatic cough and throat irritation. All through this time I had headaches and insomnia.

Around 2 months, the cold and throat issues started getting less and less frequent as did the headache. But insomnia remained. I did not notice any improvement in lung capacity etc. But I did start feeling a lot hungrier around 3 months. I have maintained that increased appetite since.

After this it was mostly the psychological effects. Insomnia continued. Anxiety was not as bad while I was awake, but I dreamt of smoking a lot. The dreams always had me smoking a cigarette, feeling extremely disappointed that I broke my streak and smoking more since I ruined it anyway, and then waking and feeling very relieved I didn't actually smoke. These dreams were less frequent with time, but I kept having them for 8 months.

After about 8 months, these dreams stopped completely too. Insomnia continued a few weeks after the dreams stopped, but sleep became better. Cold and throat issues haven't resurfaced since 5 months now.

Just my experience, yours will likely be different. But I didn't think I'd be able to quit since I thought you wean off it gradually and I was still having those dreams 8 months in. But around 8-9 months I practically forgot that I smoked, almost abruptly. No physical or psychological symptoms, though I still have some trouble sleeping.

So just push through a few more months. You will feel normal once again, but I think it will be in accordance with your individual biological cycles rather than a fixed calendar. Best of luck!