You’re absolutely correct. Your psychiatrist “lost it”. His outburst was both unprofessional and unacceptable. None of the discussion was necessary or helpful to your mental health.
That being said: Doctors are human. Sometimes they make mistakes. Sometimes their own stress gets the better of them. You inadvertently encouraged the conversation by stating another point of view.
In your situation, I’d be deciding whether the success of the current medication and the undesirability of starting over with someone else outweighs the possibility of having to put up with future outbursts. If you only see him every few months for medication, not for counseling, maybe you can ignore the negative experience and resist the temptation to engage in such a conversation if he brings it up again.
If, however, he’s been your therapist as well, I hope you will consider a change to someone who you feel is more respectful of professional boundaries and who won’t stress you by insisting on opinions you find offensive.
Your treatment is for you, not for your treater. It’s absolutely okay for you to take care of yourself by moving on.
I wish you well,