Suggest Treatment For Foul Smell From The Nostril

what is causing a foul smell to be only in my left side and not the right? I can lay down on my left side and it goes away, or I can rinse with saline and it goes away, not permanently just temporary. I have been on countless anti-biotics, decongestants, all kinds of medicines over the past 3.5 years. Two different surgeries and the problem persists. I have seen some of the best doctors around my area and nothing. Wasted Trips! I NEED HELP!!!