If you genuinely, truly, absolutely, cannot bring yourself to vote for the president of the united states, please just show up for elections anyway and vote for your congresspeople and local representatives.
If you cannot bring yourself to vote for the president because he's so disgusting of a candidate you morally cannot bring yourself to cross that line, then PLEASE vote for your congresspeople and local representatives who can block, defend, or present new bills, actions, acts, etc.
These are the people who can actually confirm or deny or impede horrendous acts when they happen.
Like. This is the bare minimum. If you cannot vote for the President, please just still vote for someone.
Change doesn't happen if you don't vote for the people willing to enact change.