This is such a tough spot to be in. I'd lean toward the email route first since $215 + timing risk is a lot to gamble on a retake.
If you decide to retake though, worth doing a quick grammar refresh before the writing section specifically. Tense usage: https://learn.kotoenglish.com/grammar/general/tenses/ is one of those things that's easy to get subtly wrong under time pressure even when you know the rules. Small thing but it adds up across the essay.