Platy Fry Development?

[blafontaine]

I am new to all of this but my Mickey Mouse Platy had babies a little over a month ago. I was not prepared so all but one died. She was pregnant again, but this time I was prepared. She was squared off so I put her in the breeding tank expecting her to have them in the next few days. She didn't. I noticed all of sudden she wasn't squared off anymore, she was showing signs of stress, but she was still huge like she would pop any minute. Week later, still nothing so I moved her out. A few days later, I made my own quarantine breeding area for her by taking a plastic starbucks cup with a lid and poking holes in it. She was squared off a few days later so I put her in there and put rocks on the top so I wouldnt float all over the take and it would stay at the bottom. Well later today she had them. But about 3/4 of them are dead. A lot of them are still in ball shapes like they were too squished in her belly. Only a few are swimming and they only do to get air at the top. But they are all large, almost as big as the fry from the previous batch (which is over a month older) I need some advice or help or Something?? I think they were in there too long. ANyone else experience this? Oh and there is about 20-30 fry

thanks!