Try this: Go someplace public where you can eavesdrop on someone else’s conversation and listen carefully. I’m not interested in what other people are saying here, but how they are saying it. Listen to how they form their phrases, when they switch speakers, how often the over-talk each other, etc. Now go one step further and write it down – exactly as they said it – and see what you’ve got.
A mess – that’s what. Even your six-year-old nephew would know that’s bad writing. How can that be? It was a real conversation, why doesn’t it read like one?