Honor 8 — stuck in Emui

Hi,

I have a Honor 8 that I dropped into water 4 months ago.
After my attempts to dry it it worked again fine, but the power button and the volume + button did no longer work.
Since some days there was a system update that I should do, but only after the battery was empty it applied the update on its own and I ended up in the recovery menu.
Now I'm stuck because I can't download the recovery files as it always gives me an error nor doe a reboot or shut down lead me back to the normal working mode.
Sometime I also get the menu choice for a "wipe data" which I also did already with the same effect - I'm still stuck in that EMUI menu.

Is there a way to escape?
Can I use the micro SD and boot with an image from there?

Thanks for your help!