If the machine would not boot, I am assuming you ran a Boot CD to attempt to fix your hard disk?
Unfortunately, a third party hard disk utility should not be run on an encrypted disk, since it will be unaware of the filesystem and may make inappropriate changes.
It is possible that your data is lost already. However, I would not initialize your disk just yet, as that will reduce your chances of recovering the data even further.
Our recommended steps always begin with backing up the disk prior to making any changes. So, if this disk may contain important data, back it up with a sector by sector or bit for bit backup utility. Then work from the new backup copy to attempt recovery procedures.
Our recovery procedures are available at the following location :
Drive Encryption Diagnosis and Recovery - Symantec Drive Encryption & PGP Whole Disk Encryption - http://www.symantec.com/docs/TECH149679
Ideally, you will have a second computer where you can install Symantec Encryption Desktop, then slave the disk. After SED is installed and the disk is slaved, you can run the commands as described in section 2 of the recovery article to attempt decryption or to access the filesystem.
Feel free to let me know if you need clarification of anything. I'll be happy to help. Also, if this resolves the issue / answers your question, please mark this post as the solution.
Best Regards,
Phil