The trouble with growing Fittonia outside of a terrarium is, it's difficult to fulfil its need for high humidity. It likes very bright light, but not direct sun, even, warm temperatures and, as said, high humidity. Misting once a day probably isn't sufficient, but removing the plant from its outer pot and standing it on a pebble tray should help. That involves finding something that's bigger than the pot, placing pebbles inside, filling with water so that it is halfway up the pebbles, and standing the pot on top of the pebbles in the middle, so the pot is not sitting in water. The tray should be kept topped up with water - this will evaporate and provide more humidity around the plant.
The other difficult area is watering - it's best to water the plant thoroughly by giving a good soaking, then allow it to drain down freely, and stand back on the pebble tray afterwards. Water thoroughly again when the surface of the soil in the pot feels just about dry to the touch, and the same ongoing. You can still mist the plant two or three times a day, that will help too. Some growers advise using tepid water to water with, others don't worry about it, so that's up to you, but certainly the water you spray with should be tepid, not cold. More info here https://www.thespruce.com/grow-fittonia-houseplants-indoors-1902486
Because your plant looks a little limp right now, I suggest you water it thoroughly immediately, and if you do that while it's still in the outer pot, empty that out after 30 minutes, and again 30 minutes later if there's any more collected inside.