Weird smell in my Nose that comes randomly

[jlsoto3]

So about two days ago, i had allergies and i was having the usual stuffy nose and watery eyes(this happens every year cause weather change)  i guess i thought it passed but now now time to time i blow my nose,and when i inhale from my nose, i get this bothersome smell, its not like a nasty smell but rather an unpleasing one, it makes it hard to eat and i cant explain what it smells like, and it smells sort of sweet but a nasty and really bad smell, its hard to explain,When i eat something sweet it makes my stomach turn, I'm barely 18 and i'm worried that this will continue and affect me in school and work, any suggestions.This is the first time this ever happens to me