To me this is about her personal experience. I remember reading an interview in which she said about having an accident at some point of her life which prevented her from pursuring a career as a professional ballet dancer. She said that she started to write songs out of sorrow that she felt after learning she won't be able to become a ballerina. I guess this song describes how she felt when she first learnt about this ("She said sorry but you're never gonna dance again" may refer to a doctor/nurse) and how she tries to overcome the physical inability ("my feet just keep me moving, trying to break the chain, and I feel like running").
To me this is about her personal experience. I remember reading an interview in which she said about having an accident at some point of her life which prevented her from pursuring a career as a professional ballet dancer. She said that she started to write songs out of sorrow that she felt after learning she won't be able to become a ballerina. I guess this song describes how she felt when she first learnt about this ("She said sorry but you're never gonna dance again" may refer to a doctor/nurse) and how she tries to overcome the physical inability ("my feet just keep me moving, trying to break the chain, and I feel like running").