Did you think of weather, air pollution (Chemtrails, smog etc.)?
Are you rested?
I also suspect that your sinuses may have collected dirt over time and diving brings that down into your Eustachian tubes.
What you can do is:
- Take hot shower in the morning, on your forehead, knock and massage you sinuses, press the pressure points for sinus drainage. Sniff in the stuff the gets loose, the hot steam helps to loosen up the rest.
- Rinse your sinuses 'hella yeti"
- Make sure you're rested well.
In the water:
- Make sure you head stays warm, wear a swimming cap under your hood in cold waters.
- After each dive, close one nostril and 'resonance sniff'* up through the other anything that may have got loose or come out during the dive.
- Like said before, dive slow, relax more and equalise soft and often, avoid pushing too hard. When you encounter such moment, slowly return. On the surface do rubbing and knocking on your sinuses with 'resonance sniff'* cleaning thing. Usually you'll have the impression that it's cleaner soon and you can and gently try diving again. Within 2-5 'cleaning' dives your dirt should be cleaned up and you can dive until your ears truly get tired.
Using this I succeeded to clear my sinuses and ears after they blocked up during competition warm up dives - in the old days

, or when I was having a cold or just old dirt blocking my sinus airways.
Let us know how it worked out for you!
Love, courage and water,
Kars
*resonance sniff = sniffing while you with your nose partially block the airway causing a snoring sound and vibrations which aid in loosening and transferring the mucus.