Come on PC we know you can do it. Keep them warm and lightly watered- damp. Most overdo the watering in this early stage and wonder why their plants take so long to grow. It's bc there is not sufficient oxygen exchange to effect metabolism from the waterlogged soil.
@GreySeer's suggestion of a dome can help get your humidity up and
@Cannalicous's suggestion to trim up the leaves is also something to consider doing. Feed/Spray the
tops of the remaining leaves with something as simple as a pH'd kelp solution. Get the leaves off the ground so they can breathe properly. Or if too much hassle, cut your loses and focus on the plants that are responding.

Mu