my husband was so drunk tonight that he tore off MOST of his big TOE nail. What do I do?

Yikes. Make sure it's clean (hydrogen peroxide works great) and bandage it with whatever you've got. Unless there's some serious bleeding going on, it shouldn't be a big problem-- but make sure he doesn't catch it on anything or rip it further. Once it does start to heal, buffing any weird/painful edges down with a nail file might help to make the healing process a little more pleasant.

There really isn't much you can do for his torn toe nail. Generally, finger and toe nails don't bleed very much, just have him keep it clean, wrap it up with a bandage and eventually the nail will turn black and completely fall off on its own within a week or two.