I recently tried to synchronize anki from my phone and from my computer to ankiweb, but when i synchronized I lost all the decks from my computer that I have made, and only got the one from my phone uploaded to my computer. I did not save my decks before i synchronized. Is there a way to undo what I did, and find my old decks again?
Once you’ve restored your backup – it sounds like you’ve got 2 different collections. Since first-time syncs are one-way, you need to preserve one collection so you can re-import it after you set up syncing. Syncing with AnkiWeb - Anki Manual