This is conflating causation and determination. It is true that one's choice must have a cause, and this can either be internal or external to oneself. But it is not true that the choice must be _determined_ by the cause. The Agent Causation [0] view denies the notion that only states or events can serve as causal priors, and instead asserts that substances themselves may be the terminal "cause"

[0] https://plato.stanford.edu/entries/incompatibilism-theories/...