90% of bad breath problems are due to dental issues. Basically, food gets into the tiny pockets between the teeth and under the gums, and there it decays. Just imagine having a couple of grams of rotting food stuck in your mouth - horrific! Add to this a good layer of stale plaque and dental calculus (scaling or 'tartar'), which also harbours bacteria, and no wonder there's a howling pong!
A couple of visits to a good dentist and hygienist, and possibly a good mouthwash, and the problem will disappear. Working with my dentist, I saw this problem many, many times. Mouthwash on it's own is unlikely to do the trick, although it might disguise the stink a bit.
Even more importantly, poor oral hygiene can cause all sorts of horrible diseases which I won't go into here - but heart disease and cancer are two of them.
Everyone really must go to the dentist, even if they're terrified - but there's really no need to be afraid.
Snoring is not something I can comment on - I don't think anyone has a foolproof 'one-size-fits-all' remedy, because there are so many different causes. It's very hard to live with, tho' - my late husband could keep the whole street awake!