Even if 99.9% of people lose money, someone has got to be in that 0.01% that gains! Why not you?
What i will say though is that you need to be very committed to doing this in order to succeed. The ability to take losses is a plus too, even if you have a 90% winning strategy (rare indeed)- you will still be losing 10% of the time. You need to be able to adapt quickly and constantly redefine how you trade in order to survive the changing conditions. What at first appears to be a 'holy grail' of trading can quickly turn into the best way to give away your cash.
You are doing the right thing by trading a demo account, keep up the good work. You should soon be able to tell if you have what it takes to continue- not just by the balance of your account but from your own reactions to your trades as you win/lose- you must be very self-critical and strive to forever better yourself and your position.
Trading is by no means guaranteed money, but with careful planning and risk management, you can keep your risk to a minimum... and the rewards are definitely worth it.
I think the longer you are in the markets, the more you realise how little you know and how much there is yet to learn. Time to take stock and decide to either go at it 100% or to just quit.
This is serious business, not a game, and should be treated as such. What you put in you will get out as in any other field (although some people choose to gamble and do get lucky too- but if i wanted to gamble i'd rather go and back a horse).
I hope you choose to take up the challenge and continue. (capital allowing- please don't get into debt to trade!).
UKTraderGirl