Do I have sinusitis

So my nostrils have been blocked for months now, and I'm breathing out of one nostril most of the time with the blockage alternating.

The only time the blockage lets up is during exercise and sauna and it's usually only partially in one nostril, congestion is worst in the morning and I've got a constant post natal drip.

Doctor perscribed a steroid nasal spray and it did nothing and I'm now waiting on a nasal wash.

Probably the most annoying ailment I've had and just wondering if what I described checks out with you lot on here.

Thanks!