Dear Kaushik,
I can understand your problem as well pain. You have trying to overcome your habit for years but of no use. You know habits cannot be removed from life, but yes they can be replaced. Evil by Divine. Bad by Good, Negative by Positive. There are two types of Bad Habits One where you cause Loss or Pain to others like stealing money, Second where you hurt yourself as smoking or drinking (Even indirectly have an impact on your family).
A small technique yet effective sharing with you. E.g. One has a bad habit to waste time in useless TV Programs, they can replace this with habit of reading good books. No overnight miracles. First shut TV in breaks instead of changing channels then slowly reducing time and increasing reading time. Same way if I want to reduce number of cups of coffee I drink per day. E.g. 4 Cups, I replace 2 cups with Tea, Then further reducing one cup of coffee and one cup of tea with warm water. And this way changed habits from 4 cup of coffee to 1 cup of coffee per day.
All habits are not bad, like rising early in the morning, Walking etc. But what is bad must be replaced. It sounds easy and simple but in fact not so, as it required lots of patience and determination.
Taking to physical or Mental status, Know there is always difference in disease or habit. There is nothing permanent. Even our body is also a type of machine. It consumes fuel through what We eat or drink. Keep on charging. Like you can change configuration of your PC, Hard drive, RAM, ROM, Operating Systems etc, Same with physical body and mind. Change in weight, thinking patterns, emotions by training and discipline of your mind in certain limits.
Further You can search on Google on various techniques to make change in habits and apply what you feel most effective with positive mind and complete faith on Baba Sai. Success will be gained.
May Baba Bless You!
om sri sai ram!