ahsanAllahu ilayk ustadh i struggle with the bad habit of smoking and it leads me to other sins do you have any advice

Fasting can really help you quit smoking because it forces you to stop for a very long period of time. One of the most important pieces of advice I can give is that if you hang around people who smoke, you need to stay away from them while they are smoking (at the very least). That environment is what will keep dragging you back to the habit. Another thing is to throw away any packs of cigarettes you have. It becomes a hassle, both financially and physically, to have to go and buy them every time you feel the urge when you don't have any on hand. With a strong will, dependence on Allah, making dua, and turning to Him, you can succeed (insha'Allah). Remember that persisting in a sin makes it a major sin. With that mindset, you will quit, bi-idhnillah, Az-Zawajal.