When you start to get sleepy, stand and do jumping jacks for 60 seconds, or take a jog around your building. Something physical to get your heart pumping should help to keep you more alert.
Hey! I was in the same position as you. I followed this method (https://www.top-law-schools.com/forums/viewtopic.php?f=6&t=224488), and I get a 174 on an off day. Just got a 180 right before my August test. So I def would recommend!