I don’t think that you were “totally” off-track. However, 50 quotes just aren’t enough to give you a meaningfully fine-tuned model. My diagnosis is that the model badly overfit your data, and hence repeated the texts verbatim.
Another possibility is that your prompt to the FT model was not appropriate. From the guide
To use such a model you can write a few starting words of the haiku, and let the model complete the haiku. You could also let the model generate new haikus by increasing the temperature, and sampling from the model with an empty prompt. Use the stop sequence END during inference, to ensure the haikus end in the right place.
First few words of the required quote need to be provided. so either your text needs to have a “quote from bob”, quote from Tom" prefixed in each instance; or you would have to write the first few words yourself.