I wish I could give you a good answer, but I’m not a doctor (at least not a medical doctor). All I can tell you is that according to the nasal cycle it’s normal for most people to have one nostril with a reduced airflow. But then it’s sometimes one nostril and sometimes the other that’s congested (it changes every few hours). It’s also only a slight congestion.
Whether you’re nasal septum is deviated or not I can’t tell. But if it was, I guess it should always be the same nostril that’s congested. To find out you would probably have to ask an otolaryngologists (ear, nose, and throat doctor).