I know what you mean about the symptoms being distracting from school and feeling like it's better to wait.. I have approached it that way and ended up failing my courses because I was more focused on drinking than studying, and the paranoia that came with the morning after withdrawals led to some serious clashes with instructors and floor nurses who eat their young as it is. No. Bueno.
I wasted a lot of time waiting for there to be a perfect time to quit. That "perfect" time for a lot of us ends up being a "rock bottom" moment, those are pretty darn horrible and we don't want you to have to go there. I am not saying I think you will progress that far, but if you think you are having a really hard time stopping drinking alcohol, you could be on those train tracks already?
How about a trial sobriety? But start right now. The withdrawal is going to feel like having a bad flu. It's really not that bad, and it's only a couple days. You should feel more refreshed within a week. Trust me that is much more conducive to studying!