There is a looooong thread somewhere in the archives here of when I second had fry. (First was before kokos and the frustration brought me here). I was so sure I could raise at least one to be a goldfish, but they kept dieing on me - at 2 weeks- at 3 weeks- at 4 weeks- couldn't understand why- I only had one little fry left at 5 weeks and I cried when he finally passed too. He had albino eyes! The thing is, it isn't easy at all. You need to be there to feed them 4 times a day and then there to remove the food they dont eat an hour after they have eaten. Its the only way to keep the water good enough. And even more than half will always die within the first month or two. I think you have done good to get yours this far- full bodies and looking like little fish. Most peoples' first tries don't even make it to here.
You have to stand back, be unemotional and know that it takes the average Joe owner, at least 3 tries at fry raising to get ONE or TWO fish eventually out of a batch. Those are the real facts. As you will know if you read all the failed attempts in this forum. It is because it is such a big challenge, it is because you have come so far at nearly making it, it is because you care about it at all, that this will not be your last time and chances are next time you will get your few healthy big fish survivors. Don't give up. Practice makes perfect. I know it is painfully sad but it doesn't mean you cannot do this, or that you did badly, because you didn't, who knows why many fry do not make it for reasons that are not our fault...it just means having come so far and having learnt so much, you should try again