really need advice about how to move forward from this - I'm really beating myself up over this, and I don't know how to stop.
I was where you are at right now at about the same age, but I continued on and being an alcoholic it got worse!
I reached the point where I did not draw a sober breath for 5 years, I drank when I did not want to drink because in order to feel "Normal" I had to drink every day.
Do some reading about the progression of alcoholism, you will find that if one is an alcoholic the longer one drinks the worse it gets, it never gets better or levels off, it always gets worse, the only way to stop the progression of it is to totally abstain from drinking.
Why not take this test
Alcoholics Anonymous : Is A.A. For You? along with some others just to give you a chance to decide if you are an alcoholic.
If you decide that you are an alcoholic then the best thing to do is to stop drinking and STAY stopped.
If you find that you can not stay stopped then the sooner you realize that the quicker I would suggest you find a recovery program and work it to the best of your ability.
I use the program and fellowship of AA to not only stay sober, but to live life to it's fullest sober. There are other programs, choose one and WORK it! Work it FULLY, not half way, half measures in dealing with alcoholism avail us NOTHING!