One of the most powerful quotes that applies in many countries and situations around the world is "If voting actually mattered, it would be illegal".
On a national scale this is largely the way how things work. Don't get too invested in any one particular candidate or person because they are selected rather than elected. Voting nationally is a game of who gets the most money and can convince the powers behind the curtain that they will obey. The best success we have is to vote and elect local leaders over our communities. That is where we have the best chance to start to drive change and improve ourselves and our communities. Nationally it's largely a waste of time so don't get too upset on that front. If you have local elections, participate in those as strongly as you can! You will be able to gain much more satisfaction and see results much better than something on a national scale.