Vicious circle after update: keyboard + Google Apps won't work

Apparently I should not have installed the latest update. But I did.

My keyboard does not work since. The tricky part is that I cannot reinstall the Google Apps either. I have been there, I know the widget that should help, but all it says is that Google Apps have been installed already. Please note that I cannot restart my phone due to problem #1: I cannot enter my password because the keyboard does not work. What can I do? Can I do anything? And is there a way I could have known this before installing the update that has apparently been around for a while now? Any help is very appreciated. Thank you!

(I do not think I am alone with this problem; links to other forum posts dealing with the same problem are of course also very helpful.)

Plesse use the search function of the forum (little magnifying glass on top).

Actually there is a topic with almost the same name as yours: