I have met many full time traders during my career, I have seen their accounts and I have even negotiated with them. My short answer is: yes, you can!
Let's say that you are already a good trader and can make 500 pips per month. So, the first question is: do you have the initial capital to make a living operating in the Forex market? If you have $ 1000 and you are trading micro-lots, you will get $ 50 per month (in this example, I am taking a currency pair like EUR / USD). So, can you make a living negotiating with Forex? Of course, no.
How much do you need? It is up to you, the initial capital to become a full-time trader is different for everyone. But, if you do not have enough money to invest, it is better to start out as other leading traders did, as part-time traders to get additional income. If you try to reach the amount you want, just by increasing your positions and your risks, you are likely to lose all your money.
You should focus on building your own Forex strategy that allows you to earn money constantly every month, do not focus on making a lot of money really fast, because it will come with time.
So my suggestion is to start as a part-time trader, become the best part-time trader of all time! When you feel confident and have the capital to make a living just by trading in the Forex market, then become a full-time trader.