How do I prevent a runny nose during training and sparring?

This annoys me to no end as whenever I try to go hard as I can against a bag for a 3 minute round, I start sweating down my nose and it leaks fluid all over my mouth. I find myself constantly shoving my nose over my shoulder to wipe it off and going for my towel between rounds. I never have this problem when I do cardio or work out, but during boxing, I just get incredibly drained and my face sweats like I've just finished a chili eating contest. I don't know if it's the same for everyone else and they just deal with it (snot going in your mouth) or if it's just me. Is there something I can do about this like some kind of nasal spray or pouring salt water through my nostrils? Last thing I want is to be in a match and look like some 10 year old kid getting the snot beat out of him. Speaking of which, my nose gets incredibly itchy when it starts sweating and the only thing that makes me forget about it is getting punched in the face - any remedies for this as well?