LR help

Taking the flex in 2 weeks, and LR is crushing me. I do sections and get around a -8, then in BR I check my flagged questions and usually end up at a -5 (my goal). Whenever I look over the questions I think "of course the answer isn't this" and end up picking the correct answer. I guess my issue is the time and pressure, but how do I overcome this? Any tips would be appreciated!