I didn't say your vote is entirely unimportant. As far as it goes to help select the 100% of electors in your particular state who will cast the vote for your candidate, it is very important. But once that slate is chosen, your individual vote does get thrown out and no longer counts in the choosing of the president. And if your candidate happens to lose your state, then your vote is completely wasted because it won't matter for your candidate in any way.
In my case, my vote is virtually wasted, because in this political era, the Democrats have Illinois completely sewn up. If Illinois were to get to the point where my vote might be as important for choosing our slate of electors as your vote in Michigan is, then it will be practically wasted anyway, because that would mean the Republican is swamping the Democrat nationwide.
So please, go vote, and good luck.