I am happy to help you today
Do you think that you stop breathing at night?
Do you snore?
Do you ever wake up gasping for breath?
As long as you don't have high blood pressure there are over the counter nasal decongestants that you could use periodically at night to open your nasal passages.
However I would recommend seeing an ENT ( Ear nose and throat) doctor.
They could perform sinus xrays to check for any blockages or infection in your sinus cavity.
It is possible that you have allergies though and maybe some allergy medicine would help.
Your bad breath is likely caused from bacteria in your mouth but you could have gastric reflux too that could be causing as well as dental problems or H. pylori bacteria in your stomach.
Make sure to mention all of that when you see your physician.
In the meantime continue with the saline nasal spray.
You can spray with the saline spray as often as you would like and should probally a few times a day to keep your sinus cavity from drying out.
Let me know if you have more questions.
You are welcome.
I am here whenever you need me.
Have a great day!