Re: indoor sage.
Sage needs a lot of light and prefers excellent drainage. It is difficult to give it enough light indoors, unless you have a sun room or greenhouse. It is also not at all tolerant of over-watering. My guess is that your sage was over-watered, which can cause the roots to rot and then the leaves to wilt. If you catch it soon enough, it is sometimes possible to save a house plant with rotting roots by re-potting. Remove as much of the old soil as possible and expose the roots to air before putting in fresh soil- preferably better draining soil. Try mixing some cactus potting mix or perlite or sharp sand or grit in with regular potting mix to get a better draining mix and look for potting mix with a small percentage of peat moss.
Basil also needs a lot of light but is not as much of a stickler for good drainage as the sage. It will probably be fine, but I would move it outside for the summer to give it some extra light and fresh air.