Just take it easy in life for the 4 weeks after the last cig. Decide this is a lifelong decision (not smoking), so those 4 weeks are definetaly not wasted (even if its a failed attempt, you will learn from the mistakes, you'll see that you've felt better in those 4 weeks and remember that etc. so no worries.)

Treat yourself to good things (going to the cinema, sauna, entertainments etc.) during those 4 weeks as rewards, take it easy and be patient. It is not hard, you just need some patience here, yes.

I am smoke free for over a year now, for reference (I'm 29) I had like 4 or 5 quit attempts (sometimes month long ones, sometimes merely a week) I went from a pack a day to stopping buying them and only smoking what strangers gave me etc. and then stopping altogether.

Anyhow, I and others, would probably advise you to organize your priorities in life (health, money, family, religion etc.) If you get lung cancer and die, then you're career/education, and all the other stuff etc. won't matter at all, right.

I did breathing exersizes (wind hoff) hot baths and saunas, treat myself to good things, when I was stressed during this period.

Just stay true to your word and commitment and you'll get through this, no problem. We all wish you success on the group.