Learn to play the game. You don’t have to answer all the questions. Sometimes it’s to your advantage to not answer. For every 4 questions you get wrong, you get 1 correct answer deducted. So if you get 20 right and 8 wrong, you’re only credit with 18 right. If you answer 20 and left 8 unanswered, you're credited with 20 right. In both scenarios, you have 20 right but in case #1, you get a lower score.
With a 920 total, you probably got a lot of wrong answers so a lot of points were deducted.
Take a practice test and see how your score changes when you answer everything vs only answering when you know it’s 100% correct.