Yikes! -- sounds like you're hurting, for sure, but maybe there's a few things that might help you out ...
Do you have a boot disk for Linux? If so, you can use that to boot Linux and perhaps get access to your Linux partitions. Then, backup your data like crazy (maybe multiple times); you can always re-install the O/S, but your data can't be reproduced easily. No boot disk? Try using your installation CD; if you can get to a command prompt, you can try to mount your Linux partitions and recover your data that way. No boot disk and not able to get to a command prompt from your installation CD? Manufacturers often include utilities to copy a drive with their disks; often, the utilities allow you to specify one or more partitions to be copied. If you have space on your C: drive, you may be able to create additional partitions and use the manufacturer utility to copy data from your D: drive partition(s) to the C: drive.
To use Linux to recover your NTFS partition, you will likely have to have a boot disk with a kernel that knows how to read NTFS partitions -- which RedHat does not support. If you know any other Linux users who use a distribution such as Mandrake or Slackware, they may be able to create a boot disk for you that will allow you to access your (Linux and) NTFS partitions.
Hope this helps -- more info appreciated.