You need to re-install, yes, but you can still save your stuff.
Uninstall FH com.plete.ly. Do not make any backups. Presets, maps, and such will be saved, so don't worry. Delete the FH file from your C:\ harddrive. Make sure it is deleted completely. Don't worry, all of your stuff should be saved in your Recycle Bin. To access the recycle bin, just go to your Control Panel and the Recycle Bin should be there. If not, check your desktop. Still not there? Search your entire computer for it, because every computer has a recycle bin. Re-install FH. Again, download the SETUP, not the patch! The file should go directly into C:\. The file wll then be named C:\Feralheart. Go into your recycle bin, and "Cut" the Feralheart folder. Then simply go into C:\Feralheart and paste it in there. Some outdated files may / may not make FH crash.