Non-votes literally do not matter, mathematically it's the same as if you had two votes and you gave one each to both candidates. Parties cannot appeal to you as a non-voter because they have no idea what you want, the only way they can is if you vote in primaries for your candidates of choice so they can see the sorts of things their constituents value. Only don't vote if you truly don't care whether we have "fascism or fascism-lite", because if you would prefer one then not voting only helps the other win.

Again, general elections are about harm reduction, sometimes you have to be an adult, grit your teeth, and choose between two bad choices because one is clearly the better option. We'll have to eliminate FPTP first if we want anything different.