It sounds like it could have gone worse. I will throw out that if you keep talking, you might want to address those things with her you said that you know aren't really helpful. I assume you DO want her to take you seriously, so suck it up and say you said that stuff because you could tell she was uncomfortable, but if you don't think this is just a passing fancy, don't try to downplay it.
"Donīt take it too seriously; itīs just something that has occurred to me but it doesnīt mean I am going to do it".
"Maybe after all itīs just a craving for affection and what i need is just more friends"
I think it's great that you know just where you were hedging the truth, and the fact that she apologized for her (normal) reaction seems like you two will have pretty good success communicating, even if the outcome doesn't end up being you staying together and being polyamorous.
If she is willing to read a book about it after she reads the information you are presenting her with, I would recommend "Opening Up: A Guide to Creating and Sustaining Open Relationships" by Tristan Taormino - I DO recommend previewing the first couple pages on amazon, if you think she'd be put off by how the book opens (which I was a bit) then I'd suggest "Love In Abundance: A Counselor's Advice On Open Relationships" by Kathy Labriola.
I like the fact that most poly books were both written by women, it imagine it's easier for women to hear new ideas that way if they are wondering if poly is all about men just wanting to have more sex partners. I know other people have favorite books, it's been awhile since I read Ethical Slut or Polyamory: The New Love Without Limits which are ones I also hear a lot should be the first one to read. I think reading books with her and picking and choosing the ideas that do or don't work to build the infrastructure of what poly could look like for both of you by choosing together, instead of you just saying "I want this" is often easier on all parties.
Good luck, I hope the conversations continue to go in an OK direction, and that there's some poly friendly counselors in your area on the resource guides!
Happiness will never come to those who fail to appreciate what they already have.