@Eichhörnchen
as long as you do not give up painting at all (would be a shame!). So there is no money in it?
Apart from "free art" have you asked in museums or public places, for remittance work of pictures with a certain content, that suits your interest?
Whatever, it is already good to have received an invitation for an interview, this is not self-evident today in the "world of work" as you rightly said!
I do not know you too well but from what you write and post i take you could be a very good teacher, with enough background and patience.
Wish you the best, and tell us what happens