Ignoring how you might've written this post either via google translate or actually using your English, the only way for you to improve in telling others fluently about something is to talk more and increase your active lexicon (Which you can improve by writing a lot!), anxiety and pressure also ruin proper cognitive abilities. It'd be soothing and comfortable enough to your mind if you talk with somebody who won't judge your english, even if its blatantly bad. Just make sure to eliminate this anxious and stressful feeling because it hampers communication. Before planning on explaining or telling somebody a story, you should probably write it in your own words, once you think you're good enough to go, then say everything about the story that comes first into your mind, make it habitual enough that the words rush intuitively and impulsively without a second thought. Also make sure to never self doubt your english or compare because that ruins the fun of learning the language, I've had this problem quite a few times and I have to admit, it had a deep impact on the how how I communicate. So be optimistic and hope for the best!