First night disaster - help!

I think Julie's question is on point. Did you get a fit pack? At any rate, try going up a size. With the P10, the sleep tech said I should use a small. It got up my nose, literally. The medium was better but produced weird whistling-wheezing sounds. The large was the best of the three, though eventually I switched masks because the large was pretty leaky for me. But I digress. A very nice thing about the large was the feeling that I was finally getting enough air.