Is it permissible to continue treatment with a psychotherapist who studied psychology, given the existence of fatwas prohibiting the study of this science, and how can one treat themselves if they stop this treatment?

There is no harm in studying medicine and psychotherapy if the student is well-versed in Sharia (definition) and avoids its corrupting influences, adhering to the rulings of Islamic law. For Sharia is based on the welfare of the servants. There is no objection to seeking treatment from a trustworthy psychiatrist who adheres to the Sharia, as the Prophet, peace be upon him, commanded seeking medical treatment.