Passed out from one glass of champagne, scared to drink now?

I know the title sounds weird lol trust me it was a weird experience.

So basically, I used to drink before no problem, I never even had a hangover, however, last July at my sisters birthday party, I passed out after drinking one glass of champagne.

I was at work all day (from 10 am til 12 am) before I went to her house, but I had some food right before I went to hers so I don’t think the problem was that I drank on an empty stomach.

When I passed out, I was in an out of consciousness for like 2 hours, and then when I woke up I puked and felt great lmao.

This was the first time this has ever happened to me, tomorrow is my best friends birthday and I know there’s going to be alcohol there, I haven’t drank since that incident in July.

Any idea why this could’ve happened to me? I’ve been scared to even have a beer since then lol