Moi, is your mask fitting you well? Does it have some metal strip or something so that you can shape it to your nose correctly? I use the metal strips from school folders
like these in my homemade masks. From everything I've heard (don't wear glasses myself, but my bf does and is fine with the masks I made for him), fogging glasses is a sign that the mask doesn't sit right, because your breath should not escape out the top where it can do the fogging, it should go out front through the fabric. Maybe you can enhance your mask with some wire that you attach at the top edge or something like this or get a better one?