Yes, you do. You emphatically do. The point of a democracy is to vote for who you want to represent you. Even in Michigan, the closest state this time, the difference was 10,000+ votes. Each individual vote is symbolic. I chose not to send a symbolic message that I want Hillary Clinton, a centrist war mongering liar whose only interest is power for power's sake to be president. I sent that same message in the primaries where I and other Michigan voters helped Bernie Sanders to a historic upset.
The Democratic party chose not to heed those lessons nor pay any attention to her unprecedented unfavorables and rigged the primary in her favor. She chose not to campaign in the rust belt states or offer anything to the disaffected people here. Hillary Clinton and the Democratic Party are not entitled to my vote, they have to earn it and they failed to do so. I didn't go around campaigning for people not to vote or whatever. I simply voted my conscience. The only way you'll get me to feel bad about it is if he won by 1 vote. But the presidential election wasn't decided by 1 vote and it never will be. Individual voting is symbolic and people should vote for what they believe in. Maybe then we might be able to vote for an actual liberal.