Helping yard chick hatch

Hi. I have just had 3 broody chickens hatch their eggs this week. All have left some eggs on the nest, I'm assuming these are no good now (not rocket science. Lol)
But my last girl left her nest this morning so I went and checked it to see how many babies were actually hers and found an egg left on the pile with a teeny hole and a teeny beak sticking out moving but there were blowflies hanging around. Not a good sign to me. So I have brought egg baby inside and slowly peeled off the shell. There was a bit of blood and it still has the yolk sak attached but the membrane around its head was completely dried out. I have managed to get all the maggots off the little thing. (I hope)
It makes little peeps when it's moved and it seems to be breathing fine. It only gets one eye opened though. I have never had this experience before (I raised the mama hens from day old chicks 2 years ago and this is the first lot of chickies). I currently have baby chick sitting on my lap and a warm wheat-bag (not hot) while I freak myself out with research on what the hell to do. According to what I have read on here, I shouldn't have helped it out of the shell. But I couldn't leave it in there knowing that it would have had maggots in with it.
Please help. What do I do now??

Oh dear, these things happen

If it still has the yolk sac attached it was not ready to hatch yet. You need to keep the chick as clean and as still as you can, you don't want it to rupture the yolk sac. It still needs to absorb the yolk.
You can use a cup or similar to stop it moving around her is an example from Sally Sunshine ~


Please check out this link ~https://www.backyardchickens.com/a/step-by-step-guide-to-assisted-hatching
It has a section on unabsorbed yolk.
By doing this you are going to need to put heat above the chick ie a lamp. Do you have a desk lamp with high wattage bulb? This can work as temporary measure for now.

Fingers crossed that your chick makes it
Please do be prepared for it not making it though.

Keep us posted,

Hi. Thanks. I didn't think it was ready but I couldn't leave it with the maggots. I didn't rupture the sak but it did come away from the shell. I quickly cleaned it up and got all maggots off and popped him on a wheat bag while I got the light set up for it. He didn't make it though. Poor little thing.

Thanks so much.

I'm sorry to hear your chick didn't make it