If I were your instructor THIS is EXACTLY what I would fix.
Now I'm more convinced of it than I was before. Your problem is that you haven't been taught an efficient technique.
Promise me that you'll at least *try* what I suggested. If you can't get it to work, fine. But it may also give you you're "Eureka" moment.
R..
I'm guessing OP is also not equalizing the mask effectively on decent. The only reason to need to blow hard or pull the mask off the face is if the mask is jammed onto your face by water pressure. Additionally/alteranatively OP might have the mask on too tight. It's counter-intutive but the main cause of a leaky mask is having it on too TIGHT. Then it leaks... so the student tightens it even more... so it leaks even more. The strap should be only tight enough to keep the mask from floating away. Beyond making it harder to overcome the pressure... being too tight (or too small) can press the nose pocket right against the nostrils.
If your mask leaks... loosen it.
PS - I coach students to "fill the mask with air" rather than to "clear" the mask. Does a better job conveying how to perform the skill.