I can't help for during the day, but I get this at night and same with dd. I have tried pretty well everything for both of us, and short of dosing myself up on sinus decongestants (dont know if theyre pg friendly) pretty much the only thing that helps is to have a humidifier/vaporiser on (doesnt have to have anything in it except water) AND a heater. The heater in particular is the one that does alot, but the vaporiser sinches it. Make sure the door is closed and the heat and humidity can't escape.
Hth