What calling you an "antisemite" really means
The Zionist weaponisation of "antisemitism" is a fascist dogwhistle. I think it's very important to identify it as such and expose what it refers to.
When they call you "antisemitic" for being against literal genocide, they are dehumanising you. At best, you're an ignorant dupe of Hamas. At worst -- and usually --- they're saying you're part of a mindless throng of bloodthirsty degenerates who will murder their babies, rape their women and steal their land.
If that sounds familiar, it should. Obviously, this is the rhetoric they use against Palestinians and against Muslims generally. But the dogwhistle originates from well known, very old antisemitic tropes. That's where you've heard it before. Zionists simply took the oldest and worst antisemitic tropes and started using them against others.
This is the subtext when they call a non-Muslim westerner "antisemitic." It's not just a form of de-legitimisation, it's a way of dehumanising you. The same thing happens if you stand with BIPOCs in North America: you're no longer seen as really "white," you're irreversibly tainted, corrupted. And objectified. And you become a target. It's all the same dynamic.
If you need more proof of all this, just LISTEN to a Zionist. They literally say who they are. Believe them.