I think you are going to be fine. You will only really catch norovirus from inhaling particles if you are directly with someone when they *v or have *d, not just by walking past a toilet that smells like *v. The virus particles are quite heavy so fall to the ground quite quickly and only stay airbourne for a small period of time. Please try not to panic, you've been washing your hands and keeping them away from your mouth and nose so you should be absolutely fine.