Welcome back Achim. I feel your pain, having been in a similar situation earlier this year.
One thing that helped me with installing apps individually was in the settings of Play Store...
My old phone has now gone from my screenshot. But at the time, I could see all the apps I had installed. So by tapping on each app in turn, I quickly installed them on my new phone. Still a bit tedious, but easier than trying to remember them all when frantic with the stress of it all.
I know what you mean about the banking problem. But my bank has decent online banking. So I didn't suffer. On the other hand, WhatsApp was an unnecessary pain.
One day, I hope you can look back on this without feeling misery. In the meantime, you have some inspiration for a few Liotes challenges! 😀
!BBH
RE: When your phone goes black !