Downloading from Ankiweb caused Anki to delete my entire collection

I’ve been experiencing one problem after the other with Anki lately. First, Anki wouldn’t open anymore. I read here on the forum that I should uninstall Anki, restart the computer and then install the 32 bit latest version. This worked as far as opening Anki is concerned. But after I managed to open it, I chose to sync by downloading form Ankiweb and one of my profiles, the larger one, was replaced by the other one and now I have two profiles with identical content. That is to say, my main profile has been deleted. The strangest thing is that this main profile has disappeared even from Ankiweb. The fact that I might have lost my entire collection is daunting. Is there anything I can do to recover it? Thank you.

Didn’t Anki tell you something about overwriting your collection when syncing? That what should happen when your collection in Ankiweb can’t be merged automatically into your local collection.

Try File > Switch Profile > Open Backup to restore your collection.

I have tried that before, but I get the following message:
Automatic syncing and back-ups have been disabled when restoring. To enable them again, close the profile or restart Anki.

I have closed the profile and restarted Anki, but it didn’t work.

This message means your collection has been restored successfully. If you didn’t notice much difference, maybe all available backups are from a time after your collection has been deleted…

Go to your backup folder (usually C:\Users\%USERNAME%\AppData\Roaming\Anki2\User 1\backups) and check the date of available backups. if you find an earlier backup, you may be able to restore it by opening it.