I am not sure, if this applies: as you installed NITDROID.

However, in addition to general flashing guide on the wiki, I had to re-flash my whole device recently as well:
[HOWTO] FLASH N900 Fremantle / Use rescueOS to Backup MyDOCS / locate FIRMWARE RX-51 files and flasher

(NOTE - first try to rescue data, at the end this flashing process sets the device to an empty state)

Before, though, I could rescue some data using the rescueOS - I described the steps how I did this as well in the guide.

If you deleted all of home, there might be nothing left. You might still be able to get some data back, if you copy the whole device as an image and apply some undelete/data recovery tools: Tools: Data_Recovery