I know the feelling well as I did the same thing for many years. From my mid-teens I noticed how alcohol and other substances improved my speech. Unfortunately, there is a number of addiction problems in my family, especially to alcohol. I began drinkin very heavily from my late teens. The root of this was, as you say, a love of the freedom of being able to speak to anyone about anything, which until I discovered the effects of alcohol was something I had very rarely done. It is a very slippery slope and I still have problems with alcohol and drug abuse. Getting involved in alcohol to achieve fluency and confidence is not a good trade; trust me. I know it is very cliche and much easier said than done, but i do believe that how a person deals with their stammer and their attitude to it does make significant changes.