Looks like your training is sufficient for below 2.
In my experience there are other factors you need to consider.
first make these hard workouts 2-3 days away from your competition.
try to alternate hard and easier workouts to let your body recover. As to pace all of the great times I have split have the first lap 2-4 seconds faster than the second, it feels like you are going faster the second but you are using the extra energy not to slow down as you get fatigued. The 8x200 is a great workout to finally lower your time, do it on a Monday or Tuesday. try to run these even or the last faster if you feel good. 27-29 average is good. If you want add in 2x300 to replace the first 2x 200s as this will put you into oxygen debt sooner. do them at 45 at first and maybe 42 after you do it a few weeks. Finally set a goal 1:59 or 1:58 and visualize the race every night before you go to sleep. I would use 57-60 as your ideal split. Also concentrate on getting to the 600 at 1:27 or 1:28 this allows you the chance to go sub 2 when you get in shape for the final 200. You have good speed with your 51 just keep it smooth and translate that into a great 800. Good Luck