"So I'm afraid I must repeat (and I take no pleasure in saying this, believe me) your only three options this election are Trump, Clinton, or throwing your vote away."
If you vote for someone you believe in, your vote is never thrown away. They may not win, but people will see how much support they get, and that can lead to more support next time. You are right though, that FPTP is a poor system. It's particularly poor when it comes to electing presidents because (as far as I understand it), it is not possible for two candidates to combine their votes in any way, unlike parties which can combine their votes and form a coalition. The upshot of this is that people like Bernie Sanders won't risk standing as an independent for risk of splitting the left wing vote. You could have a system where candidates can pledge to transfer their votes to another candidate in the event they fail to secure enough votes themselves. It could bring an end to the endless oscillation between Republican and Democrat presidents.