Most of the throat irritation is hot dry air,I've never used that type but I'm betting if you use a bag instead of directly drawing your hits you'll have much less throat irritation if a longer mouth piece is available that'll help too ,pot vapor is still irritating so it won't go away.Your throat will get use to it over time and it won't bother you as much in a week or two.Your sinuses could be a couple things...vapor is still irritating that alone can inflame sinuses,or you could be allergic ... my sinus cleared when I started to vape so I really don't know I'm just taking an educated guess.