The best thing you can do is be as proactive as possible. Get yourself an intake assessment at an outpatient facility ASAP. They will probably require it anyway, but it is good to show that you’re taking accountability and you want to change your ways and are willing to actively pursue sobriety. I know many people who have faced similar challenges , some multiple times; all of their outcomes had one thing in common: treatment for the next few months. It won’t do any harm and you will feel productive taking action. I suspect your school would also support this decision. It’s a scary thing, but not the end of the world. You will get through it and be sober in the end.
I went to rehab and heard horror stories about people serving life sentences for killing people while driving drunk, many of whom have no memory of the event because they were blacked out. You don’t want to let it get to that level! Everyone always says “not me, I would never”... but you never know.