I don't blame you, I hate washing floors too.
I don't know about volontariato, when I looked into it (OK, I was also working ft but still), there was only ambulanza. Everything else seems to be church related.
Can you not get involved with your DC's school, maybe offer an English session once a week? Actually no, that's a crap idea. It was something I'd thought of doing a while back but scrapped the idea.
How about starting something up yourself? There are so many services in the UK that don't exist here, maybe some of them would work?
Other than that you could go and be a bilingual secretary just to get your confidence back initially, but the hours will be full time, so that's probably no good to you either, or is it?