The athlete told The Mirror that she felt a lot of pain when she sustained the knee injury which forced her and her partner Ian Waite to pull out of Saturday's show.
Johnson said: "I'm so upset. It's horrible when you get injured, and so close to the show was just terrible.
"It was all going well on Saturday. We'd done the dress run and I was loving the dance. I was really excited. Then as we finished, Ian went to pick me up and I heard a noise I don't ever want to hear again."
She added: "I don't think Ian knew what had happened and I was in shock. I heard it, then I felt pain and more pain. I didn’t know what, but I knew it was bad.
"Anyone in my situation would be worried about the Olympics as well as the show... If I can dance on Saturday, I will. I've had some really nice messages. It makes me want to get out there even more."
Johnson added that she trusted her physiotherapist to make the right decision, while it was claimed this morning that the long jumper had been given the all-clear for this weekend's show.