Occupation Frustration

Lately I am "stuck" in my working life and don't know which road to take... let me explain:

I come from a big family of newspaper workers (printers, photographers and journalists) my Father is a newspaper photographer and my Mother was a journalist and since the age of 18 I worked for newspapers, and some magazines too, for many years (all my working life in the U.K.) which I enjoyed so much.
So when I came to Brasil of course all that had to change for me as the language here is Portuguese and not English, so I started working in English schools as a native English teacher.

The year I arrived here the (then) government was giving away working and living visas to anyone who had gone over their 3 months to stay in the country, it was an "Amnesty for Foreigners"
So of course I applied and got my permanent visa (which is a kind of i.d card) along with full legal status to live and work in Brasil as long as I like, of which I was so lucky to get as the current President would never do anything like this for foreigners in Brasil, if it was now I would have had to leave Brasil years ago.

So off I went to the English schools, working visa in hand, and started having interviews all over the place...
To my amazement my permanent visa "scared" most of the Director's in the schools as they are so used to foreigners coming to Brasil and working illegally, of which they prefer (cheaper for them), so my visa was worthless in my new-found occupation.
I did get lots of work as all schools love to hire native-speaking teachers who bring much more business for them as most people prefer to have a British or American teacher.
Anyway I had all my interviews, chose the school who paid the most money and stuck with them... for a while.

Over the years I have had uncountable bad experiences within the English schools... I have changed schools like most people change their socks, I have been cheated out of money, been given the worst lessons (late nights and early mornings), had to travel to dangerous places (most of my lessons were outside of the schools, working in companies all over the city) and have never had the same rights as Brazilian workers have: health insurance paid by the companies, paid sick-leave and holiday pay, travelling expenses to and from the lessons, Christmas bonus, e.t.c...
So basically if I was ever sick and couldn't work, or had a couple of weeks holiday when my family visited me then I never got paid.

A while ago I was cheated once more and got so frustrated with being so exploited over the years that I ended up giving up working in English schools altogether and just gave private lessons instead.
Now I am so fed up of teaching English... I'm in a rut and I don't have the same inspiration as before... in truth it's making me very depressed.

I know what you are thinking: You have your permanent visa - why not do something else?
but the problem is unless you are in an industry (like oil) here in Brasil then it is so difficult for a foreigner to do anything else here but teach English, so I am stuck on a straight road where I really need to turn left and do something different but I have no means or chance to do so.
I feel like I am not working to my full potential and when I remember how happy I was in my work in England it makes me sad.

Don't get me wrong; I don't think I am such a special person that I should be doing something "more important" - I would clean toilets if I had to, and if it made me happy, and I'm not the kind of person who thinks that some jobs are lower than others, I see everyone as equal and always have.

I am so happy in every other part of my life here in Brasil and I love Brasil so very, very much, I just wish that I had the choice, or chance, to change my profession to something I would once again enjoy and be happy with... I feel as if I am not a complete person anymore :(