Unable to pay attention at all please help (serious help needed)🚨

I used to be a smoker until math exam

(when i realised what i had been doing and accepted my crime to my parents and they kind of already were super suspicious anyways but lets not go deep into why i used to smoke)

Since that day i am struggling to even read for 1 hour like bro even for hindi where chapters were like a cakewalk, i struggled to finish the syllabus. Only because the paper came easy i think i did pretty good. Now tiime for history and theres TWENTY CHAPTERS AND I JUST FINISHED MY FIRST ONE IM LITERALLY STRUGGLING TO READ ONE PAGE WITHOUT FORGETTING IT AND GETTING ZONED OUT. HELP PLEASE BOARDS CHAL RAHE HAI KYA KARU ABHI KE LIYE KOI TEMPORARY SOLITION

(AUR KOI BHI SMOKING KE RELATED GYAAN NA BATE MUJHE APNI GALTI PHELE SE PATA THI LEKIN PERSONAL REASONS HAI AUR JYDA DISCLOSE NAHI KARNA CHAHTA).

TLDR: i used to be a chainsmoker until math exam when i decided to confess to my parents and quit but now I'm unable to focus for even an hour without zoning out or forgetting stuff

(Please do not educate me about smoking and it's effects im well aware and always was there are some personal reasons i dont want to disclose)