I had my phone plugged into my computer earlier and was deleting files off of the sd card. I turned off the usb connection and it said it was preparing sd card (as usual) except the preparing sd card never ended. My phone then started working really slow and then I would get a black screen and after it went to sleep, the phone never came back on. I took the battery out and put it back in, but it would still do the same thing. I now have the sd card out of the phone and it is working, but of course now the phone is saying that i need to insert a sd card. what do i do? what went wrong. thanks!