How long is a piece of string, it is different to everyone and it is hard to gauge unless you go through the individual journey yourself. It is important that you take your time and not rush as thats when things can go wrong
Well depends on how whom you listen as your mentor, your mindset and live trading
Get a better mentor it will shorten your learning curve and be profitable in almost a year
Your mindset after burning your accounts or getting losses will also determine how long you be profitable...if you quit easily forget succeeding in fx... when knocked down get back up.... those losses and burnt account consider them tuition fees
Don't demo trade my man... live trade always that's where you learn to control yourself..your greed and fear ..you will tame them for uour benefit... demo trading doesn't do any of this