It sounds similar to what I faced with my crippled duckling--but that's not to say you won't have a better outcome. His legs at first were stretched out all the way behind him. After a few hours, he had one foot up under him and by the second day could shove himself around the brooder like that. The next day, he had the second foot up under him but couldn't actually walk. Eventually, he could walk--a little--but it never got much better than that--he has always stumbled around and has grown much more slowly than the others, presumably due to the fact that it takes much more effort for him to get back and forth between feed and water--even if they are right next to each other, he has to work harder just to stand and turn around.
He is still a crippled little duckling at two weeks of age. I just yesterday decided to try the band-aid spraddle-leg remedy, although for him I had to use a stick wrapped well in band-aids as the in-between thing. It seems to help him a lot--he is walking much more normally and not stumbling around so much. He had been tripping over his own feet because his legs were turning inward. He seems to appreciate the improvement.
BUT... I don't have high hopes for him in the long term. I intend, within reason, to continue to give him assistance and an opportunity to get better. But I expect he will never be fully healthy and hearty and I will be very surprised if he survives to adulthood.
I hope you have a better outcome. I know others have, and that is why I even tried to begin with. There is certainly hope. If not, just remember that you have already given him more than he could have expected in nature. I know my little Chance has had a fairly happy life and if it has to end earlier than we would prefer, at least he has had this much and I know I've done my best by him.
Good luck. Let me know if the spraddle-leg remedy works for him. I'm curious how much improvement my little Chance will show as a result of it.