Exactly the same thing happened to me back in 2018, though it wasn’t a quick a turnaround as a week! We picked up our keys in June, then were hauled into a meeting in July to tell us the night shift would be closing in September.
The arse dropped out of me, but it turned out to be one of the best things that could’ve happened in the long term. Hopefully if the worst happens, you can look back in six months time and come to the same realisation when you’re much happier somewhere else.
Keep your head up. What’s best for you won’t pass you by.