Can't breathe out of right nostril

I've never been able to breathe well out of my right nostril, but it's gotten to the point where I barely can at all. If I block my left nostril, it still sounds like air is entering and exiting my right nostril, but I feel like I'm suffocating and really have to try and breathe hard. I have pretty bad brain fog and am always sleeping with my mouth open. I've tried nose strips and they haven't done anything. I also always have to mouth breathe when I'm exercising, even if I'm just briskly walking. Should I consider surgery? Or am I being extreme? I'm just sick of the headaches and brain fog.