Hey Maudezilla - sorry about your struggles this morning, it is amazing how upsetting a little number on a scale can be
There are SO many things that contribute to weight loss and weight gain, and what it sounds like from your post is you aren't in a position where you can focus and identify them for you uniquely due to your other commitments/focuses. In addition to alcohol, there is salt intake, fat to protein to fiber, and sneaky sugars. There is TOM, and - don't want to scare you - but any possibility of pregnancy? Not to mention thyroid issues, diabetes, etc...
Not trying to scare you, but all of these things and their combinations can work on affecting what we see on the scale. It sounds like you only have a few more months of school and then can refocus on the weight. At that time, you can spend more trial/error time and maybe have a visit with a doctor to discuss things from the medical angle.
Until then, be gentle with yourself, acknowledge your stressors, and try to let them go. We all have times in our lives when we just can't focus on the weight stuff - and that's OK.
Stay engaged here, and we all are behind you 100%!