Almost 10 months free but I can't study...

[nsd_user663_52784]

I am 20 years old. I was 4 years a stable smoker.I have already made almost 10 months without smoking a single cigarette (without any patches, only will). However, there is a problem. I can't concentrate on studying. I can barely remember what I have studied after 2-3 days. The problem is that when I smoked, I studied and concentrated better. Back there, I went through the study material by smoking cigarette after cigarette and that's how I managed to memorize in order to pass some hard exams. I have wasted my last 10 months of doing nothing and wasting opportunities to develop my education. I also failed a couple of exams. Maybe my mind is playing me tricks and lies that I will concentrate if I lighten up a cigarette. I am really happy that I have stopped. I have gained some weight, started working out and saved some money. It is only this problem that concerns me and I don't want to waste everything because of it. Can you please help me or provide me with an advice? You don't know how much I would appreciate. Thank you very much.