Husband with chronic bad breath

so

This one is tough! For the first 5 years of us being together, only occasionally he would get the normal bad breath like anyone of course. After baby was born idk what happened but I noticed his breath soon became awful and I didn’t want to kiss anymore because the smell makes me nauseous. He will brush his teeth and his breath still smells awful like garbage. He’s been to the dentist and had a cleaning and still zero help. He’s laying next to me sleeping but facing the opposite way as me and we are like 2 1/2 feet apart and I get many whiffs of it. It’s so bad 😩 he went to a GI doctor because by now I think it’s a sign something is definitely going wrong with his health maybe in his gut, sinuses (he has sinus problems, he always sounds like he can’t breathe properly ever) or stomach so he’s now been prescribed a few things to hopefully help identify what’s going on. If those dont work then he will have to go to an ENT doctor because it might be the issue there. This sucks though and makes it even harder for romance or anything. Anyone else going through this?