as salam alaikum
there are three major fatwas regarding smoking tobacco and cigarettes:
1) It is haram.
2) It is allowed provided that it would not cause substantial harm to your health.
3) It is haram to start but if you are already an habitual smoker it is allowed but you should try to stop, even gradually.
Overall, it is at least definitely advisable not to smoke.
With prayers for your success.