I don’t have advice – because In the past I have also had issues with voice shaking and tears when in emotional situations. No clue if I’ve grown out of it or have just been better at avoiding them.

I need to tell someone off

You might want to reflect on if you really need to. “Fuck off” and walking away is also sufficient. Delivering via a written message is also an option.

If this is a work situation then my suggestions change dramatically.