Just a month ago, I started sneezing intermittently at home and at work indoors. At first, I didn't…

Just a month ago, I started sneezing intermittently at home and at work indoors. At first, I didn't pay attention, but now it's almost every hour, plus clear nasal discharge after sneezing. And for the past couple of days, itching in my left nostril has been added to the sneezing. It seems like allergies, but also not. I've never had allergies before, so I'm linking it to the heating season. Everything is fine outside. It used to start after sleeping, but now it's all day. I've been rinsing my nose, but it's no use. What else can help?