I am thinking about jumping in to forex for the first time...

I need to know about risk... If i put in money can I loose more then I put in and be held responible?

Lets say I start with $5000 after I master my practice account..
Whats the worst that can happen?

I'm worried because its all on margin with such high leverage 200:1

I'm told they will stop my trades if reach $0 and I will not be held responible for any losses beyond that?? Is this true? I don't want to risk my house and car!!