Have I killed this plant?

[DarlingCoffee]

I think I made the mistake of putting it by a cool window and now it’s in the bathroom where it is more misty. Is it too late for this plant? It was so beautiful :(

Give it a few weeks and see if there are any signs of recovery. What is it?

I would cut back all the leaves and stems that have gone crispy and give it a misting regularly to avoid over watering, which is the temptation. Make sure of good but indirect light. Fingers crossed.

Looks like a maidenhair fern.
Cut off all the dead crispy leaves. Keep it moist and see if any tiny green fronds appear.

Yep, trim it right back. It’s a Maidenhair fern.
Give it regular mistings from a spray bottle and in Spring feed it occasionally with Baby Bio. (As per directions on bottle)
With luck you might see the tiny buds of new growth but it will need nursing.
Keep away from hot dry spaces near radiators or in a very warm room etc.

Thank you everyone! Greatly appreciated

I've had this. Cut off all dead foliage right down to the ground, put it somewhere light, but not in direct sunlight and with as a constant temperature as possible. Unless it's bone dry, don't water it from the top, but add a little from the botton when the whole pot feels a bit light.
In the spring you should hopefully see some new shoots, at that stage I'd tip it out of the pot, and re-pot any healthy looking shoots, and roots, in new compost with some grit etc for drainage.

I keep mine on a shallow saucer of pebbles filled with water, this doesn't water the plant but makes a little damp micro-climate for it.. They can decline very quickly but, if there's still life, it will come back. As pp have said the crispy fronds are dead, won't come back and might as well go. Mine doesn't enjoy this time of year, with heating and lack of light. So isn't currently at its best. I'm looking forward to spring.

I've got green fingers, can usually get most things to flourish, and I have never managed to keep a maidenhair fern going for more than about a month.

Don’t feed it until you’ve got good regrowth

To be fair they are very temperamental. I have many houseplants some 10 years plus but I can never keep one of these alive for long. I have had about 5. I have tried underwatering, misting, various locations. They all die. My longest lived one lived for 3 months and then just turned brown!
they are nice looking though. I’d just buy another one

I'm rubbish with plants and I bought one of these on a whim and through dumb luck managed not to kill it. I've had it several years now, it's pot is very congested but I daren't repot it. It's in a plastic pot with drainage holes, in a pretty pot with no drainage, this stands on a plant saucer (about twice the diameter) filled with pebbles that I keep topped up with water. It's in the bathroom with a regularly used shower and I mist it very occasionally. I put it in the bathroom, initially, so it would be near a tap and I'd remember to water it. The other stuff came as I found out about the plant.

OP my plant looked like yours when I went on holiday for two weeks and gave it to someone to look after. It had one frond with some green the rest was dead. It took a year to recover, partly because it doesn't grow over winter. Last year, when I went away I left it in the unplugged bathroom sink, just in its plastic pot, on a wet folded tea towel under a very slowly dripping tap. It loved it.