This is a great topic to discuss and thank the op for creating this thread. I will respond in my usual point fashion

1. It is never to late to be a concert pianist. However as tmickel wrote, one has to really want it.
The point is that it doesn't matter what anyone says or thinks of your goal. If your goal is to be a concert pianist, then go for it all the way.
2. practicing for the life of a concert pianist is a never ending adventure. Your 2 hours/day are not enough. When I was your age I was practicing 4-5 hours/day, but to be fair, back then I was in France and I did quit school at 16.
Bottom line is that you need a minimum of 3 hours a day of serious and dedicated practice.
3. experience in the life of a concert pianist is gained only by doing it. What this means is that don't just talk about it. Do it!!! Look for locations where you can perform. Look for house concerts in your area, small recital series, community orchestras to perform with.
4. confidence is probably the most important aspect of this business. Over the years, you will have plenty of people thinking you are crazy, that you should forget about the idea. That is where we will see what you are made of mentally.
Disregard all the naysayers, disregard all the negativity. Focus on your goal and be positive.
5. competitions don't make a concert pianist. I know plenty of people who have won competitions and who have disappeared from the performance scene (either quitting music or teaching, but surely not performing on the regional, national or international level).
What makes a musician successful in this business is name recognition, branding.
What branding means is that for a presenter to even be interested in a performer, they have to have heard of the performer, of what the performer has done in the past and/or is currently doing. This includes reviews and recommendations.