the address on all of my bookmarks has been changed to the 1 same bookmark location I last used.??????

Are you using some third party "system cleaner" utility like CCleaner or System Mechanic? These are known to be causing history and bookmark storage corruption and data loss: support.mozilla.org/questions/1273954 There are steps how to check and repair the database integrity in: support.mozilla.org/questions/1577698 — if that doesn't work you might have success restoring bookmarks from an older backup that's saved automatically over time: [[Restore bookmarks from backup or move them to another computer]]