Is this a sinus infection?

It's hard to dx someone over the computer. It sounds like your intraocular pressure (fluid inside the eye called aqueous humor) is high (hence the glaucoma test says so per your question), which could indicate a lot of different eye diseases or maybe not one at all. See your ophthalmologist ASAP and they can tell you exactly what's going on after they examine you. If the pain becomes abnormally severe and you vomit, get to the ER ASAP! Also, your ophthalmologist should work you into their schedule, because high eye pressure constitutes as an emergency. You need to call your ophthalmologists office and tell them you have high eye pressure and explain which eye it's in. They should work you in right away if you tell them that. Also, if you can get the IOP (pressure), that will also help them to determine how soon you need to be worked in. Tell them about your pain as well. Glaucoma and eye pressure pain/high eye pressure go hand in hand. Don't worry too much. Just call your ophthalmologist and if they won't work you into their schedule, call a different ophthalmologists office who will work you in, because this could be very serious or nothing serious at all (could be a malfunctioning tonometer machine).