It appears that you are suffering from either:
1. Neck strain
2. Digital eye strain
3. Sensory mismatch from screen (Cybersickness)
Next Steps
Immediate steps are:
1. Stop your work and lie down
2. Drink water
3. Use the 20-20-20 rule: look at something 20 feet away, for 20 seconds, every 20 minutes.
1. Correct your screen and visual habits
2. Correct your physical and postural habits
3. Adjust your workstation.
Health Tips
If you still do not get relief, you may have BPPV.