Ubetido,
Take heart that your story is by no means the worse one around.
In fact, I'd suggest that it's probably a very cheap lesson by comparison, but nonetheless would have jolted you into a costly reality.
My story goes a little differently.
For years I bet on whims and fancies "what I liked in the next", like a pinball buffered from one gutterball to the next and invariably I ended up "down the guts".
I had no understanding of odds or percentages and no understanding of staking correctly. My bank was whatever I had allocated (left over) for the week and I spent every last cent of it.
To make matters worse, some weeks I actually won quite a lot of money, but then I got false confidence and ended up giving back most of my winnings...o.k. all my winnings plus more
As I had no way of checking systems, I roadtested every new idea for weeks and also ended up losing a great deal of money.
It's certainly not an easy game to come out in front over thousands of bets.
Along the way I learned quite a bit of information, probably the most information I learned was when manually compiling my own database.
The strongest filter around is the market price of the horse, knowing when it's value and when it's not is the tricky part.
The major advantage over the last ten years has been racing forums and newsgroups, where like minded punters can share information and ideas.
Whether you actually agree or disagree, it gets you thinking and once you start thinking and questioning, I reckon you're on the right path.
I no longer punt like I used to, and when I remember how I used to do it - I shudder even writing about it.
Now, I have an allocated bank, bet selectively and put a lot more thought into it.
I rarely visit TAB's these days, as I tend to think they are negative punting environments.