I'm not the best person to answer this, but it seems unlikely you got a concussion from this, most likely it is the alcohol.

I don't really drink much, but have noticed when I do the immediate effects and the after effects are much stronger than previous.
Generally everyone recommends staying away from alcohol. Personally I don't think alcohol has enough positives to make me want to risk my cognitive function worsening, so I'd say you're better off not drinking....