It's not disaster, it's a learning curve, you've learned a valuable lesson quite cheaply to be honest, it takes some people a lot longer and a lot more money to recognise a problem exists!
Don't worry about the $600, or about your friends $300, he must have realised the risk when he gave you the money, if you lose it all then that's the way it goes sometimes.
Does your system work? Did it work on
demo? Have you changed anything? Has the market changed?
If the system worked on demo and nothing has changed there's no reason it shouldn't work now on a live account, so
you're the weak link that's making loss, not your system.
I've got a solution for you, but first, did the system work on demo and has anything changed (apart from you)?
Mick