Tahajjud is so powerful, duas at tahajjud can literally be answered the same day, any pain, hardship or anything you want to work out for you pray tahajjud for it. Wake up 20mins before fajr pray 2 rakaat and pour your heart out to Allah and see how things start changing for you.
There are Muslims who drink.
There are Muslims who do drugs.
There are Muslims who smoke.
There are Muslims who have sinned over and over again.
If you see them this month, in the blessed month of Ramadan, and they are fasting or they are attending prayer -