Hello Rouzy,
Welcome to Switzerland!
There is one problem with teaching English here, most students will need some sort of "certificate" from an institution for job searches etc. Likewise, you may face the same problem when trying to get a position as a teacher.
My wife is not an accredited teacher, but she has a university degree which helped her get a job as an English teacher a few years ago. Her colleagues all seemed to have teaching credentials of one form or another.
I'm not sure how your experience will count, but you have nothing to lose by trying. I think the schools themselves will tell you straight off if you have a chance to qualify. As you know, it is not easy work, the preparation is demanding, especially for the first set of courses.
Check the postings on the board at your local supermarket, you never know what you could find there (except furniture).
Cheers and good luck.