Dunno if it's any help to anyone but when I sat my stage 2 in Feb sometimes the questions would be coming at me so thick and fast that I easily got confused as to what I was doing. Didn't know if I was answering the question I thought I was or the one that had just popped up so I paniced and it threw me which meant I didn't have time to look at the next question and when I answered that the next had popped up etc....
I found sometimes you have to "Step back" a bit and re-focus yourself, ignore the mistakes you make and re-focus on answering whatever is in front of you. Although you will only have about 3 seconds to do this in.
The most important bot of advice I can give is psyche yourself up and prepare for a bombardment of questions before the test starts but when it does try to remain as calm as you can.