Hi Medbah -
I thought that alcohol made me less nervous when I was drinking, but actually it made it worse. Turns out, the days that I wasn't drinking I was simply in withdrawl and it aggravated my nerves. The fact that I felt less nervous when I drank was just smoke and mirrors trickery.
Once I stopped drinking completely, much of my nervousness went away & I learned how to manage it effectively for the first time.
Good luck & I hope you quit. My life got so much better & I wish the same for you.