When I had a cold, I used this nasal spray that shrinks the blood vessels in the nose and makes it easier for you to breathe. It is an over-the-counter drug store item and you don’t need a prescription.
Once you stop using it, your nose clogs up or at least it feels like it because you used to breathe like a superhero for a week. The longer you use, the worse the withdrawals are.
I couldn’t properly breathe without it so I ended up using it for almost half a year.