Naltrexone is really expensive, $144 here in Australia and when I tried to get a script for it, it was quite hard. In the end I never even bothered taking it as I didn't want to spend $144 and then another $50 on booze daily. The med is meant to kill the enjoyment of drinking. It has mixed reviews so guess I can't really comment.
Unfortunately and I will tell you from experience as I am an alcoholic who's been trying to quit the last 10 years, there is no easy solution or a kill switch. It's all about surrounding yourself in a better environment, getting a good support network, seeing a psych if you need to, exercising and a whole bunch of other stuff - This worked for me until there was no more joy and I went back to drinking and am now a failed piece of shit who's been living a ground hog day style of life for the past 3 years after I finished my Masters degree.