hi yes i playing on the same computer i always do and same browser
If nothing has changed on your end, then it is very likely that something cleared your browser cache behind the scenes.
Unfortunately, if you do not have a backup of the save, there is no way for me to recover it, since all progress is stored locally on your device.
That said, if you roughly remember how far you were, I would be happy to help and manually craft a new save for you with similar progress to what you had before :)