Macbook Pro stuck at white apple logo screen

Ok my MacBook Pro got dropped on a hard floor, thats what i get for letting my little brother use it. Anyways, it started up just fine for a few days, just ran a little slower than normal. Now when i try to start it up it just stays at the white screen with the apple logo with the spinning loading symbol. I tried repairing the hard drive using the disk utility but the repair fails each time. I even tried erasing the disk to reinstall OSX but it says error: resource is busy. or something like that. Then when i try reinstalling OSX i get to the part where it says select a destination and it just says examining disks... i waited about 10 minutes and no luck, it still just says examining disks. Did my hard drive get wrecked when it was dropped? That doesnt make sense because the windows side still runs fine. So i dont get it. I tried flushing the PRAM but no luck. It still notices the harddrive in the disk utility but it notices it as Hitachi instead of OSX and Windows like i named it before (i have it partitioned). Any help is appreciated. I have a lot of work on this system and havent gotten around to getting an external hard drive for backing up anything yet so please help me save my macbook pro!