Hi ya
I quit smoking 4 and a half months ago, the first and third day were worst, try to keep busy on these days, when you get a craving sip water, i also took to sucking lollipops, ( it gave me hand to mouth, especially when i went walking as i used to smoke outside) you may find you munch more, try to keep some apples cut up or prepared fruit ( this will help to avoid the weight gain) the nhs have brilliant online support so search the site.
Most importantly keep in mind the reasons you want to give up ( mine was the amount of chemicals i was intaking)
Occasionally i still crave, in fact the other day it got so bad i went and purchased a box of fags and broke one in half to smoke, after 2 puffs i felt light headed and sick so i threw the lot away as i dont like the taste anymore, and i have not had a craving since because I know i dont want one i know i dont like smoking anymore.
Good luck i hope it goes well, what kept me going was getting through day one, i said if i can go a day without a *** then i will stick to it, once past day 3 there is really no point in going back as the hardest bit has been done.
As i said good luck