It is a popular misconception that alcohol improves sleep, while the fact is that, in the long run, alcohol decreases the quality of sleep. Smoking also has adverse effect on sleep.

Since your sleep problem is long standing, it is advisable to consult a psychiatrist, who will treat you after detailed assessment. Alcohol intake and smoking can be contributory factors and therefore, they should also be addressed for you to lead a healthy lifestyle.

Your lack of sleep during nights seems to be the result of multiple factors. Certain life style changes helps to develop good sleeping habits and ultimately in falling asleep at night.
Regular sleep and wake time
Avoid day time naps
Keep regular schedule for meals, chores and other activities
Do not do any activity after going to bed (watching TV, talking on phone etc.,)
Avoid caffeine after 2pm
Do not drink alcohol within 6hrs of bedtime
Do not eat bigmeal around bedtime
Keep the bedroom dark and quiet and at comfortable temperature
Exercise everyday and no later than 6pm
Windup all stimulating activity atleast 30 min before bedtime
Avoid over the counter sleep medications

Try following the above and if you do not see any improvement consult a doctor