I'm not sure how the "personal issues" support works in the military, but there must be a chaplain's office or some medical command you can contact:
https://www.realwarriors.net/active/tre ... labuse.php Reaching out for help when you have a problem that you find is too big for you to handle is to be commended. It is difficult to admit defeat to drinking. I was in the same predicament in civilian life.
Asking for help was the best thing I've ever done. I felt a great sense of relief after I said that I couldn't handle it anymore. It saved my life and I was able to recover. It isn't easy to break a decades-long routine.
Alcohol is a big problem for any institution, military or otherwise. Instead of punishment, conventional wisdom tells us that if a team member comes asking for help, then they need compassion and are offered a chance to enter treatment. You guys are a team.
Life is never really easy, but it can get better. Alcohol worked great for me in the beginning, but then turned against me. That's when I found out that it wasn't that easy to quit. I tried quitting by myself, but failed miserably until I was able to reach out and be with other people also trying to quit drinking, one day at a time. There is strength in numbers.
I always thought that drinking was a personal problem and that I would take care of it myself. I found out that that way doesn't work very well. This is where AA really helped me.
I hope that you find your time serving in the Marines meaningful. Cherish these days, although you may not find them easy. There is help out there. Best of luck to you.