A couple of things that may also help you. you may want to practice breathing through a snorkel (or regulator) without a mask on. As other have said it can be done in the bathtub, hot tub or pool. Any place you can just place your face in the water. If you start having problems, you only have to lift your head out of the water. Get comfortabke with this. To help with the possibility of water going up your nose, tuck your chin against your chest anytime the mask has water in it. As you start exhaling, tilt the head back to make the mask the highest popint for the air to rise into. If you need another breath to finish, then re- tuck your head, inhale & try again. I once had a student who said they couldn't breathe through their nose. I asked him if he knew how to snort. He said, "of course I do". It's exactly the same muscles used to seperate the oral & nasal air ways. Good luck to you.