How to know if someone is okay after alcohol poisoning?

So my little brother was on a camping trip with his friends. Suddenly he calls me stressing and panicking. I drove to them and he was in a very bad shape. He had drunk too much and i found out he had not eaten the whole day. I had never been in a situation like this so i started calling friends and searching online over what to do. He kept passing out, struggling to breathe, shivering and panicking. I made sure to make him stay awake and calming him down. I was hesitant of calling 911 because of not wanting our parents finding out. But later i called anyway because he didnt look to well. While in the phone with them, he got better, calmed down and i explained everything to 911. Meanwhile my brother overheard and started getting mad. The 911 could hear everything in the background and said if he is conscious and getting angry like that, its nothing to worry about, but call if it gets worse.

Later he got better, had a breakdown over what happened and thought he was going to die. I was there for him, got him food and water.

Its been now 3 hours since him being in this severe condition, but im still worried. He is sleeping in his bed and warm. Its 4 in the night, should i stay up and be there for him? Or ami overthinking?