I hate the pencil tool so much. It destroyed a symbol that i have been working with in 10 days.

Please tell me that you use either an automated backup/versioning tool or incremental file saving?

If not, learn from this experience, and NEVER work with just the one single project file. Always save multiple incremental versions, and install some kind of backup/versioning tool.

If you have saved the previous fla as an earlier version you should but if you save the current fla, there is now back, unless you never closed the fla then you can just undo.