I lost all my bookmarks, is there any way I can retrieve it?

depending on what kind of computer you have, you may be able to do a lot of complicated things in control panel that lead you to recover lost accounts. I don't exactly remember how, but your computer should automatically make something like ghost copies of older items and accounts, so all you have to do (if you can on your computer) is get someone else or do it yourself to find those ghost files and restore them to their actual size, in this case that would be your bookmarks.