Now I am more towards getting insomnia and nightmare. I don't have a problem falling asleep but I will wake up in the middle of the night like 2am or 3am. If I attempt to fall asleep and close my eyes, I will 'see' kaleidoscope (hypnagogic hallucination).
What cause me problems:
Asus Nexus 2013 Tablet (headache immediately after playing video game)
Huawei Mate 20 Pro (didn't turn on the DC dimming mode)
Dell 144Hz gaming monitor (could be due to posture, I was watching video for 1 hour straight suddenly I feel more 'alert', I went back to sleep at 9am and woke up at 11am and could not sleep for 6 hours straight, I don't usually get headache with this monitor when I watch video it really makes me lose my sleep)
Pixel 2XL screen (there was once I was one the best using the phone, next moment i got a throbbing headache)
Huawei D15 (I was using the laptop for more than 12 hours due to exam, next day I wake up with a headache)
Stress (it will cause me visual field blackout if I take in a deep breath an exhale for more than 10 minutes)
My Relief
When I switched to Poco F3 (from Xiaomi) from Huawei Mate 20 Pro, I can watch video all days long and i don't get any eye strain and headache for hours.
Arcoxia (20mg-30mg) - very useful on the onset of headache, but I heard from doctor it was not recommended too often as it could damage my gut.
Drinking a lot of water (I was told by my doctor that I need a lot of water of my height, I really started to drink a lot of water everyday, that might help with my headache)