Split screen killed all my tabs

I accidentally triggered split screen in safari. No idea how I did and boy what a pain it was to close it. I am guessing that when split screen was triggered it created a separate instance of safari. When I merged, that instance prevailed. Thus I lost all tabs associated with the original instance. I’ve checked the recently closed tabs and that only lists the tabs I manually closed throughout the day. I checked history and nothing. I cannot find the accidentally closed tabs. Any idea how I can find and restore those tabs?