How do any of us know what effect we have on this planet while we are living on it? The best that we can do is to do our best. Personally, I hope that when I die, I will hear these words directly from Jesus: "Well done, my good and faithful servant." If I've tried to do my best, then I'm sure I will. That doesn't mean winning, or success, or being the best. Once upon a time, I went to a notice board on a University wall and saw my name there with, "First Class" against it. There was no one to tell, so I went to my job as a waitress and did my shift. I had spent four years with that one goal in sight. Once achieved, it diminished and became a small entry on an A4 printout. It took me a long time to realise that it was the trying that was fun, challenging and character-building. The result didn't matter one iota.
It doesn't matter to God whether you succeed according to the world's terms. What matters is that you tried and tried your best. If you feel that you are powerless to do something about your situation, don't believe it! The very act of taking the smallest steps toward a goal: this is where you will be empowered. The most important miracles in the Bible were not the healing of broken bodies and shattered minds, they were the reconnection of lost souls to God: the homecoming.
There is always someone to tell. I just didn't know it at the time.