Sticky house

Anybody have any suggestions how to improve the smell of a house? I’m 9 weeks pregnant and cannot stand how it smells. I clean and clean but the smell won’t leave. I can’t even describe it....stale is the best way. I leave the windows open to air out and nothing seems to help. Anybody have any suggestions? Any cleaning ideas? Any products you like? I tried a simple candle and now my house smells nasty with a strong hint of candle. I have such nasty morning sickness and my house is making it worse.