How do I stop freezing up when my Cantonese speaking partner asks me a question?

I consider myself a false beginner; I can read characters reasonably well, but my brain completely locks up the second I need to produce a sentence. I’ve been looking into integrating an AI tool like Chickytutor.com into my routine to get used to real-time feedback and spoken correction, but does anyone have tips for calming the 'speech freeze' with native speakers?