Advice on 2 things

Hello I've had my machine since June (30yr female)

My nose has ben super oily, any way to help that?

Also, how do you survive if you have a stuffy nose from a cold, allergies, etc? Last night my nose was slightly plugged but felt ok to breathe until I put the mask on then I felt like I was suffocating and ended up sleeping without it for the first time

Thanks!