Can I ask at what day you assisted. I have the same problem right now and feel so responsibleIf it has been 48 hours and it hasn't hatched, then give it more time. It could mean Temps were low and the chick's hatching is delayed. If you're worried, candle the egg and check for any movement. If you see movement then leave it alone. Its a different story if the chick has internally pipped for 48 hours, then you would consider assisting.
I know we always freak out a lot when it comes to hatch day and we always think the worse, but you have to remain patient and allow them to do their thing. This chick (like you said) is not ready to hatch at all, he hasn't even poked through the membrane so I'm not sure what made you assist. I hope everything works out well and keep us updated on how he's doing! Also like you said, we live and we learn. I have done the same thing in the past, 12 years of experience teaches you a lot (and still learning).