It may have the abrupt stop of the alcohol that contributed to the seizure too as detoxing from alcohol can cause seizures.
Anyhow: glad you are ok. I had a similar experience of collapsing while running at s park and they thought I had a seizure ... Took me to ER where I swear to god those folks there were angels : so sweet, kind, caring, competent.. Could not thank them enough... I started crying ; not because I was in pain but because I was so touched; I thought to myself (and maybe said it) 'I don't deserve this'.