Uy mama, 37 weeks na kaya super uncomfortable talaga yan! A few of us went through this towards the end, and honestly it's one of those things na parang walang perfect solution pero may mga tricks, try inhaling steam multiple times a day (I know una lang effective, pero really does help cumulative), use a humidifier if you have one, and sleep with your head elevated on extra pillows para hindi gaano bad ang congestion. Since your OB already said okay ang vit C and water, that's good, pero if the pain gets sharper or you're really struggling to breathe, definitely follow up with her again because pregnancy-safe decongestants or saline sprays might be okay depending on your OB's preference. Malapit na you meet your baby, mama, hang in there!