You can make huge amounts, but I don't know anyone that does this for a living other than for big banks/investment houses.
If you are doing it on your own it is terribly difficult and stressful. Its a zero sum game, so when someone makes money someone is losing (some companies are simply hedging so they may not care). You are also competing with people that have 5 screens and all the latest information in the world and know within seconds how it will impact currencies...The reality is you may make some money, possibly through fluke, but to get good consistent returns is very hard. don't believe people and adverts that ask you to pay for a course to make 1000's. Note that your strategy has to constantly change, so not one strategy will work constantly. Good luck.