Girls, my son has been having dry nose for a couple of days now, or ma…

Girls, my son has been having dry nose for a couple of days now, or maybe it's just swelling. He hasn't slept well all night because his nose is blocked up, he's whistling, and can't breathe properly. I rinse him with saline solution several times a day, but nothing comes out. It's hard for him to breathe. I ventilate the room during the day and use a humidifier at night. What can I do to make it easier?