My Writing Score is BAD...........

Well it’s not ABSOLUTELY bad.
I used to get 800 on the Writing section until a few months ago. I kept on getting 680’s or lower on practice tests.
I don’t know what the problem is. It used to be really, really easy but now I see answers that seem right but are wrong.
Any advice? I’m taking the SAT in 2 weeks and I really need to bump up that score.