bad breath - mouth pain - advice needed 4 cat

One of my 5 cats (actually DBF's cat) has horrible, horrible breath that can be smelled 2 feet away from her head/mouth. She's been to a veterinarian who told us that it was some sort of herpes-like virus in her mouth and that it was incurable. We could (and have) given her antibiotics, but it only clears it up for a little while and then the pain and bad breath come back. The next option is getting her teeth pulled, and even that is not a definite "cure" for this....it DOES usually work, according to the vet though. In the past month, or maybe a little longer, we can tell Mony's mouth is hurting her progressively more and more. Her entire muzzle area is slightly swollen and the inside of her mouth is pretty red (swollen a bit also). Her tongue almost always hangs out of her mouth a little bit b/c (I'm guessing) it hurts too much to pull it in and the swollenness too. When she is petted and her neck stretches, thus putting a strain on her mouth, it makes her smack her mouth a lot. When she swallows (just spit, not even when eating) she does one of those chicken head things, where her head juts forward b/c of the pain, and when she eats it's even worse - she makes small yelping noises when eating dry food - and has lost considerable weight :-( (we've been making a point of giving her wet food and lots of it daily). This is such a sad thing to happen to this wonderful cat...probably the most loving out of all 5. She came as a stray, about 1 year old, and is one of those like-a-dog cats that follows you everywhere wanting love and attention and when she gets annoying about it, all you have to do is say her name sternly and she immediately takes a step back. It seems the worst things always happen to the most undeserving of them...SUCH a sweet kitty!!

Has anyone had a similiar problem to this? Had teeth pulled and what the outcome was? It's pretty major and drastic surgery and we'd love some other's opinions on this one.
Thanks Y'all!
Katherine (and Ben)

ps-we'll post a picture later this evening