Cats have an amazing sense to know how to survive...so don't worry, because they also have their very own mind!
You've done what was possible finding her...you're probably right that she's looking for a new home...

Maybe she just explores the new neighborhood...
I am sorry my words may be not that comfortable for you today, but you've really done everything possible...and of course I will enclose Patches in my prayers and hopefully you'll find out what's on with her!!!