I would totally agree with that statement because I just experienced speech anxiety from our last speech. My last speech was about the psychology behind procrastination, and I did a lot of research. I tried to add some personal experience into my speech, but I didn't really have much to say about that topic because I don't know the science behind it. I would say for my next speech, I need to start earlier so I'm done earlier, and then I can review and basically study the material earlier so I kind of have an idea of what I'm talking about. I really enjoyed talking about that topic, but I felt like it wasn't me talking. The quotes from the cites I used were talking, not me.
I completely agree with how the quotes kind of take over sometimes. You said that really well!
I always do a lot of research at the beginning as well, which usually just makes me more unsure about the topic. I also tried to add some personal experience in my last speech, but I don't feel like it was that effective either.
I agree that I can sometimes feel like my quotes and sources are talking more than me. I also have found that I need to prepare more ahead of time, so I am not as overwhelmed.