Congestion? Allergies?

My daughter is 9 months old. Until 2 weeks ago, a perfectly healthy and normal baby. Then her nose was running clear constantly. She was always stuffy and had a lot of mucus. I call her Pediatrician and he said she was too young for alleriges but could have a sensitivity to dust or something in the house. So I spot cleaned my house. Cleaned vent ducts, dusted, foam cleaned the little carpet we do have, wiped everything down. She has had a cool mist humidifier for 2 weeks now.

Starting last night she sounded a little wheezy in her mouth breathing too. Occasionally she would drop her chin to chest and reach far forward for a toy and start gasping. But as soon as she was in a normal position she was fine.

This morning I snot sucked her with my nose freda for the 1000th time so she could barely drink a bottle.

She is still stuffed and wheezy, but we have an appointment this afternoon because I don't think it is allergies. Any advice or comforting words?