It could be that you're being exposed to bright light that's often due to excessive screen time especially right now with the WFH situation and constantly wanting to stay updated with the news etc.
I'd suggest you to stay off screens and reduce the brightness of all your screens,to only let natural light in during the day and not use tubelights unless it's dark.
Splash cool water on your face frequently in work breaks.
Sleep well and stay away from screens for an hour before bed.
After a 48 hour period of doing this, notice if there's improvement.
If you still don't feel the flickering has subsided , please consult an ophthalmologist even if online.
Next Steps
always look away from the screen for 20 seconds every 5-10 mins and blink to prevent dryness of eyes.