Personal Independence Payment (PIP) query

Hello, have any people here applied for the Personal Independence Payment and been successful? I have a telephone appointment on Monday and I know it will be a hard interview, uncomfortable in places. I know not everyone is awarded it. I feel like I am overthinking it and stressing myself out. My ASD mentor said I have a good case to support my application but I know others who haven't been successful first time and have had to appeal the original decision. Any thoughts/advice welcome. 

Thank you