AnnaL
I see a lot of good advice here. I hated clearing my mask...in fact it is not really a fun thing when I do it now. Water up the nose really sucks and I don't like water in my eyes much either.
Get yourself in a "zone" of relaxation, focus on breathing, fill your lungs (with air hee hee), close your eyes, pop your mask, keeping breathing normally with eyes closed and mask flooded. Tip your head back, put your fingers at several places across the top of your mask and breathe out normally through your nose. Take another breath from your reg if you want to. Don't worry about getting it done quickly. You can let the mask rest back on your face and breathe out through your nose without more water coming in too. Sometimes I find myself breathing in through my mouth and out through my mask, especially when I am cold. Weird, eh?
Another thing that might help is kissing the water good morning. My instructor always had us dunk our face in the water before donning the mask. Saves you from the shock of the cold water when you flood the mask.
Keep with it, take breaks, have fun, laugh....