Come back when you learn basic statistics. Your individual vote is practically worthless. The odds of being the deciding vote in a national election isn't any better than winning the lottery. Even if your candidate wins by one vote, there still is a good chance that the president will act differently than promised and enact policy that would harm you anyway! Trying to determine policy by voting is like trying to make money by playing the lottery. You could do a hell of a lot better by using your time and energy doing something that actually has a good chance of making a difference.
Voting gives you a good feeling that your voice is being heard, but how can you be heard when 100,000,000 other people are all talking at once? Democracy feels good but with a country as big as the U.S. you can take the outcome of elections as given.