I use Afrin occasionally, and it can dry me out. If your nasal passages were dry, that could account for the bleeding but with the clots, I tend to agree with the forceful equalization.
Have you tried saline rinse? I use the neti bottle almost every day but especially in the morning before diving.
I don't know how forceful equalization could result in bleeding from the sinuses or nasal mucosa. Maybe local trauma if you squeeze your nose too hard, but squeezing harder doesn't help you equalize.
Best regards,
DDM