“A few days ago it threw a breaker … I tried the reset button and nothing happened.”
You tried the reset button on the water heater? Or you reset the breaker? Does the breaker reset?
If the breaker does not reset, you could have a problem with the element(s) OR the electrical circuit.
If the breaker resets, and the button on the water heater resets, you could have a bad element, bad thermostat, among other things.
Depending on whether the breaker resets or not I would either recommend calling a licensed and qualified electrician (if the breaker does not reset) or a licensed and qualified plumber (if the breaker does reset).