Hi Donna, I would recommend digging into the questions you're getting wrong to determine if there's a pattern. Are they related to a specific knowledge area or topic? If they are, focus on reviewing that specific area. If they're related more around question phrasing (i.e. what to do first, best answer, etc.) practice can help with those.
It's not uncommon to get "studying fatigue". I found taking a 2-3 day break helped me disconnect and allowed me to come back to studying refreshed. If you have been studying for a long period and can afford it in your exam prep schedule I recommend it.
Good luck.
Kyle