I too had this problem and had to surface on my pool dive. My instructor came up with me and asked me what was up. I had already had surgery on my nose for a deviated septum and prior to the surgery had no water going down my throat. Now I do.
My instructor was pretty cool and told me that I wasn't alone in having difficulty. He told me the best thing to do is to concentrate and get a mental picture in my head of breathing through my mouth when I take my mask off. Taking off my mask underwater was breaking my concentration. I practiced just breathing underwater with my mask off to get used to it and then putting my mask back on but not tilting my head back to blow with my nose. I blow with my nose facing forward and then again until I feel comfortable. Water doesn't go up my nose and I only tilt my head when I feel comfortable and not before. Good luck.
My instructor was pretty cool and told me that I wasn't alone in having difficulty. He told me the best thing to do is to concentrate and get a mental picture in my head of breathing through my mouth when I take my mask off. Taking off my mask underwater was breaking my concentration. I practiced just breathing underwater with my mask off to get used to it and then putting my mask back on but not tilting my head back to blow with my nose. I blow with my nose facing forward and then again until I feel comfortable. Water doesn't go up my nose and I only tilt my head when I feel comfortable and not before. Good luck.