Head and towel over a hot bowl of water with Vicks in it? Baby saline spray to clear your sinuses? Honey and lemon drinks? How far along are you?
Deffo Vaseline around your poor nose.
Basically do what you would do for a baby with a stinking cold.
My midwife did tell me I could take co-codamol if I got a prescription from the doctor when I had terrible sinusitis. He also gave me Piriton as it can dry up a cold. Get to the GP for a checkup, they won't mind seeing a pregnant woman to advise on meds.
Currently 38 weeks and in the same boat so reading with interest. Have been taking paracetamol to deal with sinus headache and it's doing nothing. I'm taking the approach of plenty of water and plenty of rest in the hopes that it doesn't last much longer.