• I am currently on day 14 of 18 day Mahasi noting retreat in a nondenominal buddhist retreat center. I have been practicing Mahasi noting fore 6 months for at least an hour every day before this retreat. Before that did a two month retreat on open awareness last summer. I have been practicing an hour a day for 12 years, mostly Mahyana Buddhism
• I have a teacher on this Noting retreat and he has identified that I crossed the A&P on retreat. I believe i am now in the Dark Night and have been for the last few days because of the straight up dark weird shit, chaotic attention, despair, hinderances, etc. that is coming up. 
• My issue: I am physically and emotionally exhausted from practicing. I don't want to stop now! I read Mastering Core Teachings and I need to keep going, but when I note, I get a throbbing pain in my forehead and behind my eyes. Also in my chest. Am I pushing too hard? Any advice on how to direct control effort in this stage of practice? Thank you in advance. 

Samatha. Ignore the noting instructions. Noting will happen on its own. Decisions you make now count double. So make them count!

Maybe this post seems relevant:
https://www.dharmaoverground.org/fi/discussion/-/message_boards/message/2405128

What were your teacher's instructions? Is the pain bearable? Could you foster more equanimity with the pain and see the impermanence of it(all the shifts and changes in locale and intensity)? You could try noting once every out-breath as Shargrol recommends.  Have you tried just being present and and noting without labels? Does the pain go away? Notice everything else going in your experience too, "sure there's pain, but what else?" In the dukkha nanas you really want to foster (shamatha) relaxing and centering as A. Dietrich Ringle suggests. All in all, stay present with the sensations that are presenting themselves and don't shy away. Very simply. Have a confident attitude, equanimity is right there and the lessons you're learning in the dukkha nanas is that "can I be fine even with this?" Keep going, but gently.. no need to bear down or grit, just be aware and present. Laugh at the pain because it's Mara throwing everything they've got at you. 

Thank you Zero and A. Ringle, that is helpful. I will go forward gently. Metta and gratitude to you both! 

Talk to the teacher about it - I assume you did not as you don't mention that. Practicing with a teacher yet seeking instruction outside is a recipe for trouble. Stay offline. Good luck!

Honestly I am getting some sort of left frontal cortex pain when I note too. Not sure what to do about it!