It's impossible to give you an exact time when that feeling will leave you because everyone is soo different, but for me it was around 3 & 1/2 -4 months when the cloud totally lifted and everything clicked for me, I started feeling very positive about quitting and did not allow any negative thoughts enter my head, I'd nip them in the bud the minute I'd start thinking negatively, my outlook changed and I started to love the new me,
For the first couple of months I kept going to bed early because I still wanted my "reward"smokes at night when kids went to bed so I had to go to bed to keep sain, same in the morning I really did not want to get up and I had to get 3 kids up and ready for school do I had to get up and I was very miserable in the morning, loved my morning smokes with my cuppa before kids woke up, that was the hardest one for me, I would get up and have a shower and put lots of yummy body moisturiser on, I found it helped me not want to smoke cos I didn't want to lose my yummy smell lol then I'd have a big breakfast and then suck on mints, gradually the mornngs got more bearable, I started going out for tea/coffee in the morning with friends and ordering a delicious cake.
Now I can hand on my heart say the thought of a smoke in the morning turns my stomach now, just as the thought of an evening smoke, I swear to you it gets better than better, it will be better than the best smoking day you ever had.
Thinking about it, I got extremely comfortable in my quit by the 6th month, so to be honest I would say it was month 6 were I was happy out and cravings/thoughts were few and far between, give yourself as long as you need but you will get there that I promise you,
It is essential that you reward yourself constantly, those cuppa and cake in costa coffee, starbucks etc really did it for me, I'd even go on my own and read a magazine.