Is this ok for my rabbits?

well, as you all know, my rabbit babies keep dying, but this litter i am deterined to keep alive. I have them in a box, with a folded up towel, then a bunched up one to snuggle into,then, all fur and sawdust and their nest. to feed them I lay the doe on her back and let the babies to there thing. is this ok? I keep them in the box in my room. Its the smallest in the house, so no one goes in, and its warm and cozy.i have put them way back on a shel in between cupboards, to keep them falling off, with a towel hanging across the cap from cuobard to cupboard, so the area is dark. The box is big and roomy, and they seem fine and wriggling an warm, but is this ok, am i doing things wrong?