Stop holding your nose and blowing, to clear your ears. You can burst your eardrum this way. I have a perforated eardrum, myself (though not from this), and getting a subsequent inner ear infection in that ear is the most painful thing I have ever experienced. Worse than the burst appendix or broken ribs.

Instead, try holding your nose and closing your mouth and swallowing a few times. With a big gulp of water might help. Should eventually give you enough pressure to clear the blockage, without risking your health.