Perhaps is not at all a medical issue but just that you’re someone who thinks very, very deeply and needs time and extra effort to translate your inner conversation into an interpersonal conversation. You might try being very deliberate about summarizing your experiences as you go; after you’ve read a book or seen a movie, spend 20-30 minutes summarizing the plot, highlights, and what you liked/disliked. Then you’ll be more prepared to have a naturally flowing conversation about it. It’s a bit like preparing for school work; don’t expect yourself to be good at replying off the cuff if that’s not one of your strengths- prepare instead!